Practical Sex-Ed, Ch 5 [M+F+] [Oral] [Incest]

* [Chapters 1 & 2](https://www.reddit.com/r/eroticliterature/comments/ejile1/practical_sexed_ch_1_2/)
* [Chapter 3](https://www.reddit.com/r/eroticliterature/comments/ek0ba0/practical_sexed_ch_3_mf_oral/)
* [Chapter 4](https://www.reddit.com/r/eroticliterature/comments/ekevwp/practical_sexed_ch_4_mf_oral_incest/)

### Chapter 5

The students were all now back in their seats. Ms. Callahan was happy at how things were progressing. The girls had done very well in their practice session, even if many of the boys hadn’t lasted very long. What more could they expect from horny young boys, many of whom just had their first blowjob?

But now it was their turn to return the favor.

“Now, cunnilingus is similar to what you all have already done, but more focused on pleasure. We will be demonstrating that now. Pay attention boys, because your practice session will be next.” Ms. Callahan hopped back up on her desk and lifted one leg, placing her right foot on the desk and once again revealing her luscious pussy. “If you would do the honors Mr. Francis.”

“My pleasure.” he responded. With his hot young coworker sitting on the desk Mr. Francis walked over and knelt down level with her crotch. It truly was a lovely thing. Basically fresh out of college. His mouth watered. He hadn’t tasted a pussy besides his wife’s in years. He smiled at his coworker and then leaned in. He began with a long stroke up and down and on either side of her labia, repeated the process two, three more times, before moving up to focus exclusively on her clit.

Ms. Callahan gave a soft whimper of pleasure as her coworker’s tongue flicked back and forth across her clit. “As you can see, class, Mr. Francis is focusing his efforts primarily on my clitoris, which is where most of the pleasure for women comes from. Kissing and licking the lips is pleasurable, but not as much has the clit. When your partner is going down on you you can provide some direction by placing your hands on their head and giving slight nudges.”

She ran her fingers through his hair and slowly guided his mouth up and down her crotch, “You can also provide additional stimulation by inserting a finger or two into the vagina and making a ‘come here’s type motion along the roof of the vaginal canal.”

As she spoke David moved a hand up and inserted two fingers as he continued flicking his tongue across her clit as her fingers ran through his hair. This time last year he never would have guessed he’d be eating a pussy this young ever again, but here he was.

“A good way for you to help your man is to place your hand on the back of his head and guide him where you want him to go,” as she spoke she placed her hand on his head, “maybe you want to push him down to the vaginal canal, or maybe you want him to make sweeps across the whole labia.” She guided Mr. Francis’ head as she spoke, “or maybe you want him to go down even further for some anal stimulation, like we saw earlier, which is technically called analingus.”

As she guided his head down David focused his tongue on the young teacher’s asshole, pushing in while using his thumb to continue stimulating her clit. ‘Pretty soon,’ he thought to himself, ‘I’m gonna fuck this hole.’ How did he win this jackpot?

Ms. Callahan guided his tongue back up to her clit, and as she did so he shifted his thumb down to her anus, not wanting her to lose-out on any stimulation. Here he remained, concentrating on her clit, two fingers in her cunt and a thumb up her ass, until he began to feel the sharp spasms welling up inside her. The orgasm rocked her body and she held David’s face tightly against her crotch until it subsided.

*Christine/Thomas*

One by one the students came to front for their practical exercises with their partners. Thomas and Christine were up first. There was a yoga mat for Christine to lay down on with a cushion for support. She walked up and sat down.

“Alright Thomas, now just help her off with her shorts.” Ms. Callahan said.

Christine was nervous being the first female student to get naked in the class, Thomas was nervous about seeing his first live pussy.

He looked at Christine and tried to smile but it came off as awkward, which she returned. He moved closer and she helped him by pulling them partway off her hips. Next came her panties, and Thomas caught his breath. She was on display before him, before the whole class.

He leaned in clumsily and began to kiss and give small licks to the young pussy in front of him. Christine watched him as he did. He tried doing what he’d seen Mr. Francis do, tried finding and focusing on her clit. He flicked his tongue up and down, side to side, around in circles, and kept on, and kept on, till soon his tongue was tired and the girl still hadn’t climaxed. ‘Is it supposed to take this long?’ he thought to himself ‘Am I that bad at it? I had no idea my tongue would get so tired of moving around…’

‘Why can’t I just cum already’ Christine kept thinking to herself. It felt pleasant, but it just wasn’t building up to anything.

Finally Thomas pulled back and looked at Ms. Callahan, who seemed to understand.

“It’s ok Thomas, it’s your first try, and it can be hard for a girl to climax if she’s nervous. Many women who wait until their wedding night to have sex often don’t orgasm the first few times. So don’t worry Christine, you’re not abnormal either, it’ll just take more practice and comfort.”

Thomas was comforted by his teacher’s words. So was Christine, she was worrying for a bit that there was something wrong with her.

*Brianna/James*

Brianna and James came up once the other two students had returned to their seats. James felt less nervous now, at least he couldn’t do worse than Thomas. Brianna wasn’t nervous, even if James couldn’t make her cum, she could help him out.

She sat down on the mat and spread her legs and gave a wink and a ‘come here’ finger to James. She was wearing a skirt, which she simply drew up around her waist, giving James a great view of her already moistened panties.

He moved forward excitedly and pulled her panties down her tanned legs to reveal a tantalizing young pussy with just a bit of dark hair at the top. Brianna pulled him in for a kiss then guided his face down to each breast, letting James lick and suck her brown nipples, and finally guided him down between her legs.

She guided his tongue up and down her lips, into her hole, back around again, and then up to her clit. “There you go, right there, stay right there.” She spread the top of her lips to give him better access and let him go to town. He wasn’t the best, but he was ok. Even still, after a few minutes she could tell he probably wouldn’t be making her cum.

The hot hispanic ran one hand through his hair and then began guiding him back down, over pussylips, across her taint, till his tongue was on her asshole, her lower back and legs raised up off the mat to give him better access.

“Yea you like that ass you dirty boy.” she said when she felt him press his tongue hard against her asshole. She kept his face pressed there while she began to rub her own clit.

“As you can see class.” said Ms. Callahan, “It can be helpful to provide some self-stimulation during oral sex.”

James now grabbed her hips and pushed her back till her knees went down near her face with her ass up in the air. He moved his knees forward for her lower back to lean on and then let her pull his face in between her smooth tanned cheeks. With one hand on each of her luscious asscheeks and her hand on the back of his head he lapped her holes until finally she pulled his face in tight as her orgasm hit. She rubbed his face in circles around her pussy until she was satisfied, and then released him.

*Annalee/Rick*

Annalee came up next, clearly nervous, her bra now back on but her shirt still open. She wore a long cotton skirt, which even sitting on the mat covered almost down to her ankles. She couldn’t believe she was about to be exposed to her whole class, ‘How immodest!’ she thought. This was supposed to be something only sluttier girls like Brianna did.

She sat back and took a breath and focused. She could do this. If she’d been put in this situation then some good had to come of it, that’s how providence works.

Rick walked up and knelt down in front of her. How lucky was he, about to be the first guy to ever see Annalee’s cute Christian cunt, the first to lick it. He’d thought about it often. She was one of the prettier girls in the class afterall. Long blonde hair halfway down her back, adorable smile, bright green eyes.

She was sitting with her knees almost to her chest. He moved forward and put his hand under the hem of her skirt and slowly began to raise it. When it finally game to the of her knees he pushed it and let it fall into her lap. Her long smooth legs were in front of him, and her soft cotton panties just peeking through between them.

Reaching down he caught the band of her panties on either side of her hips and began to pull them up, up her thighs, over her knees, and then down again.

Placing a hand on each of her knees he slowly spread them apart. She was looking down and away, and his eyes drifted straight down to her crotch. It was wonderful.

‘They can all see me,’ she thought to herself, her face turning red with embarrassment, ‘It’s ok, you’re strong, you can do this.’ she reassured herself.

Rick ran his hands along her legs, sending a shiver through her body and causing goosebumps to rise. Then there she was, the cute little Christian girl, the one who always followed the rules and made sure to read her Bible each morning, spread-eagle with her tight young pussy on view for her classmates, a light blonde fuzz accenting her soft pussylips. Rick leaned in and she gasped as she felt hot breath on her crotch for the first time, of a tongue running across the folds of her vagina, spreading them to expose her button clit, and then of lips enclosing around it; it was so wrong, but the shots of pleasure that the tongue sent through her body sent a conflicting message.

With one hand he reached up and began to massage her breasts as he kept lapping at her clit. It all felt quite good, ‘That’s why it’s meant to be saved till marriage!’ But it did feel nice.

Rick tried his best to bring her to orgasm, wanted her to badly, her breathing was getting somewhat heavier but ultimately his tongue tired out. Maybe she was still too nervous, like Ms. Callahan had said.

*Annalee/Alan*

Rick returned to his seat and Alan came up and took in the display before him. The cute Christian was still there, spread eagle, skirt up around her waist. She looked up at him as he knelt down. ‘Great, now him…’ she sighed internally.

‘Maybe I don’t get to be the first to eat out her cute Christian cunt, but maybe I’ll be the first to make it cum’ Alan thought to himself. She was so very cute. He’d never imagined he’d see her gorgeous pussylips up close.

“Are you ready.” he said smiling at her. She caught his eye for a moment but didn’t say anything, simply turning slightly more red in the cheeks, which still probably had his dried cum on them even if it wasn’t visible. None of the girls had had the chance to properly wash afterall. There was definitely still dried cum from both him and Rick on her blouse.

He leaned forward and gave a kiss to her cheek, then down her neck to her ample breasts, kissed them, licked her lovely nipples all while goosebumps popped up across her chest, and then moved down between her legs.

He started with kisses, then licks to her pussy, then focused on her clit. She was already warmed up so he didn’t have to do much of that. One thing was for sure, he was determined to make her cum, to have her know he was the first one to make her little Christian clit climax.

Eventually he began working a finger into her pussy as he continued rubbing his tongue across her clit. Her pussy was tight, as expected. He then began taking longer strokes up and down her pussy, going gradually lower each time until he was running from her taint up to her clit.

He wanted to make her cum, but he also wanted to have his fun.

As she felt the tongue of her unbelieving classmate go lower and lower she braced herself, and then it finally hit, his tongue against her asshole. She gave a slight squeak and clenched up. Not to be deterred Alan continued probing his tongue against her sphincter, trying to gain better access.

Noticing the difficulty he was having Ms. Callahan intervened, using the opportunity as a teaching moment (one Brianna hadn’t needed), “Now, if you’re trying for analingus and you’re at a bad angle or just want fuller access you can turn your girl over and go from behind. Here, let me help.”

Alan rose and Ms. Callahan guided Annalee, turning her around. She had her kneel and bent her over till her elbows were on the mat. Ms. Callahan then raised the young Christian’s skirt to expose her bubbly heart-shaped ass, then reached down to spread her students asscheeks (much to Annalee’s surprise). “There, now you have full access. Annalee, if you would hold your cheeks open Alan will have a much easier time.”

Annalee shifted so that her chest was propped up on the cushion and reached back, spreading her asscheeks for the boy behind her. For some reason this felt much more humiliating for Annalee, spreading her ass for her whole class to see, for this boy who she’d tried to convert so many times, telling him how to find forgiveness for his sins. It was the hottest thing Alan had ever seen, and he dove in, eating the innocent Christian ass with a passion.

As his tongue probed her asshole he reached down to rub her clit. He wasn’t just going to make her cum, he was going to make her cum while getting her ass eaten. He wanted her to remember that as her first orgasm, a pagan eating her ass.

His tongue pushed past her sphincter as his fingers worked on her clit. Her breathing got heavier, her weight began to press back against him, and her pussy was clearly wet. He knew it was working.

‘Oh Jesus Christ forgive me…’ Annalee said to herself as the pleasure began to build her. She began grinding her ass back against his face, and the combination of the rubbing on her clit was too much. Alan was only slightly caught off guard at the sudden convulsions that spread over the girl’s body as she let out a moan of “Oh God in heaven…” while her anus tightened around his tongue as he fought to keep it embedded in her asshole.

When she collapsed on the cushion Alan gave her buttcrack a few final licks, kiss one of her buttcheeks and then leaned forward, “God you have a delicious Christian ass.” he whispered in her ear.

Annalee lay there for a moment longer before collecting herself, repositioning her skirt, and making her way back to her desk.

“That was so hot.” Brianna said as she walked past, Annalee simply kept walking.

‘How could I orgasm from that?’ she asked herself, ‘Please forgive me Lord.’ But it was ok. She’d followed her teacher’s instructions, and that was what was important, honoring those in charge. That thought brought comfort to her.

*Randi/Jason*

When Randi came forward this time she was less nervous than before, at least this time she wouldn’t have to touch a boy’s dick or get any more cum on her. She could still smell where it was dried on her, and she still hadn’t put her shirt back on that she’d used to wipe it off.

Jason came forward and smiled. Randi gave a sarcastic smirk back and rolled her eyes. ‘How can girls get turned on by them? How weird is it to have them go down on you? Just gross.’ she thought as he leaned in between her legs and pulled down her basketball shorts. He’d hooked her panties as he did and they came off as well.

He started to lick her, and she was relieved that his face was smooth. She looked down at his hair, ‘I can work with this,’ she thought, ‘Just pretend he’s a short-haired girl… an unskilled short-haired girl.’ she added as he clumsily lapped her labia.

Still, it was mildly enjoyable. At first she closed her eyes and imagined herself getting eaten out by someone else, and that worked for a while. Then she changed tactics. What if she thought of it as a way to humiliate the guy, to put him in his place? That thought worked a little more. She let it flow through her. She took his face and pulled it in tight, not wanting to smother him, but just to rub it in, she was going to be in control.

The blonde lesbian tightened her hips around Jason’s head and rolled him to the side, then onto his back, so that she was on top. Now she was straddling his face. She looked down at him. Although he was not necessarily upset about the change he was surprised. She pressed her pussy down onto his mouth and began to rub.

Jason felt her pelvic bone push into his face, then her pussylips pushing onto his mouth and nose. He held his breath and licked as she pushed her weight down onto his face, happy that she didn’t weigh more than she did, being moderately petite.

“That’s right fucker, eat it.” she said just loud enough for him to hear, “You wanna eat I’m gonna make you eat it.” She slid back and forth on his face, “And eat my ass while you’re at it.” she continued as spread her cheeks and pushed down onto his face, her asshole against his tongue and her pussylips against his nose. “Eat my ass you fucker.”

When she could tell he needed air she let up just long enough for him to catch his breath, but only just.

Jason couldn’t tell what to make of it. On the one hand it was hot, this juicy lesbian pussy being shoved into his face, her tight asshole pressing against his tongue and mouth, but it *was* hard to breath. It was making his erection return, he knew that much.

Finally he felt her begin to shake and give out a little moan as she rubbed her clit against his mouth, and then she rose, grabbed her shorts, and returned to her seat. Jason lay there for a moment to catch his breath and followed. He had to admit, that’s not how he expected that to go.

*Bryn/Bryan*

After a few more sets of students Bryan and Bryn returned to the front. Bryn sat on the mat and dropped her panties, wanting to get it over with. ‘This is going to be weird, but it’s ok, it’s just biology.’ she reassured herself.

Bryan leaned forward in front of his shapely high school sister, his face even with her flat, trim stomach. He could still barely believe just earlier this morning she’d sucked him, swallowed his cum. It wasn’t natural. But here they were anyway.

He looked up at her and she looked back. He couldn’t tell if she was disinterested or just putting on her best Stoic face. Boldly, he put his hand lightly on the inside of his little sister’s thigh and caressed the warm, soft skin just above her knee. When she didn’t say anything, he moved his hand higher up her leg until, at last, he slid it over her pantied slit.

After a few moments of rubbing through her panties Bryan reached up, hooked his fingers under the waistband of her small panties, and rolled them down her slender legs and off her feet. The sight of his little sister’s exposed pussy gave him butterflies and he could feel the smallest hints of electricity in his groin. ‘How can it look that sexy… it’s not supposed to look sexy to me…’

Mounting his willpower he reached up once again and began to rub his fingers along the sides of his sister’s small pussylips, a quiet moan emanating from her as he did so. Exploring even more Bryan put his other hand under his sister and caressed the soft, smooth skin of her little ass. Sliding his finger down inside the deep, narrow crack of her butt. Coating his finger with his sister’s wetness, he dragged it up and down through the valley of her ass and over her asshole.

“Try inserting your finger into your sister’s anus, and then go on and lick her vagina.” Ms. Callahan suggested, wanting to move things along since Bryan seemed to be taking his time a little much.

After several passes over her asshole he timidly, but firmly, pushed the tip of his middle finger past the puckered opening and into his sister’s butt, penetrating up to the first knuckle.

The elastic tightness of her butt opening squeezed the tip of the finger and Bryan was able to push about half of his middle finger up into his sister’s asshole, and felt the smooth walls of her rectum cling to it. Bryn sighed and Bryan felt his sister push back against his finger, trying to get more if it up her asshole and inside her. He stroked back and forth several times, the tight entrance to her butt gripping his finger as it slipped about half way in and out.

Keeping one finger up his sister’s ass Bryan leaned his head forward and began to kiss along his sister’s pussy and then licked from bottom to top. After a few passes he licked to the top once again and stopped over her clit, focusing on the small bud.

Bryn gasped sharply and let out a quiet moan. “Oh God, that feels good,” she whispered above him. She hadn’t meant to say it out loud, hadn’t meant to say she was enjoying her brother sucking on her clit. Still, she put her hands on her brother’s head to steady him and keep him where she wanted.

“Oh, God…” the teen whimpered again above her brother as he maneuvered his tongue back and forth across her clit. Bryn’s head was tilted back and her eyes were closed as she concentrated on the sensations between her legs being created by her brother’s tongue and hands. Her breath hissed through her teeth as the tip of her brother’s tongue continued to graze over her sensitive clitoris. Tongue and fingers began to move in and out together in rhythm, arousing the teen even more. ‘How is he this good? Is he just a natural?’

Round and round her clit he circled his tongue, occasionally moving his tongue down and into of her soft, wet, pink hole while while his middle finger continued moving gently in and out of her tight asshole. The pleasure made her start to squirm, her hips gyrating back and forth as she moaned softly.

“Oh, yeah… mmmm… I like having your finger up my butt Bryan.” She said a little louder and more clearly, remembering that Ms. Callahan had suggested dirty talk. ‘Is that part of the grade?’

“I want my big brother to make me cum.” she said, “Make me cum Bryan, make your little sister cum.” It was almost as if a huge dam of pent up passion had burst open. Her words entered Bryan’s ears and he seemed frantic with desire as he consumed his sister’s cunt, licking deeply into her pink, wet pussy.

Bryn tried to spread her legs as wide as possible, pulling her brother’s head into her crotch with her hands. Within moments her teeth clenched and, with a sharp intake of breath, her whole body seemed to tense up and quiver ever so slightly at the same time. Her silky smooth inner thighs suddenly tightened around her brother’s head as she let out a high, soft, whine.

Bryan could feel his little sister’s asshole clench around his finger; her entire body seemed to be paralyzed from the intensity of her orgasm. Bryan stopped, not knowing whether he was supposed to continue while this was happening or not, his finger still buried to the hilt up her tight, silky little butt.

After a minute her body started to relax and she let her breath go in a long, easy sigh. Bryan slowly slid finger out of her ass and gently took her legs off his shoulders. His face was soaked with his sister’s pussy juice. With her orgasm subsided she tried to put her clinical face back on.

“Very good work.” said Ms. Callahan as they returned to their seats. Bryan was rocked with conflicting emotions. It had been hot, but it was still his sister, ‘Why isn’t it just one or the other!’ he thought to himself as he took his seat and looked at her sitting in front of him. Even as the other students went through he had a hard time taking his eyes off the back of her head, it was all so weird.

A few more students went through. Scott managed to make the pale redhead Stephanie climax, though Robert failed at getting the little Asian Katelyn to do so.

*Emma/Philip/Seth*

Philip came forward with Emma, the cute little ebony nerd. He slid her tight khaki shorts off and then her flowery panties and she looked wantonly at him through her glasses. She was new to all this sex stuff, but she knew she wanted it, wanted to have these cute white boy between her legs like she’d seen in the porn she watched. She reached down and spread her dark pussylips to reveal the pink inside and did her best to smile seductively.

Encouraged by her enthusiasm Philip leaned in and began to eat out the cute black girl.

Ms. Callahan looked at the clock and realized she needed to speed things along if they were to get through all their activities for the day. “Slightly unfair I know, but Seth would you please come forward, we’re going to need the two of you to practice at the same time if we’re to keep on schedule.”

Emma was shocked, but aroused. Unfair indeed, but she was gonna have two cute white boys between her legs. Seth came up and at first both boys tried to clumsily approach from the same angle, which clearly wasn’t working.

“Try shifting into the position you saw Brianna do earlier.” Mr. Francis suggested, “That should make it easier.”

Taking the teacher’s advice Philip lifted Emma’s hips till her weight was on the top of her back and her butt was up in the air, her legs hanging down along her torso. Seth moved around to the other side with little other option than to straddle the black girls cute face. With her smooth ebony ass in the air each boy dove in, Philip tonguing her ass while Seth sucked her clit. She was in heaven, never dreamed she would have two cute white boys eating out her holes, that was something only cheerleaders and other more outgoing girls did.

Occasionally one of the boys would slip a finger into one of her holes, and while at first she didn’t like the feeling of a finger in her ass with time she got to enjoy it, fingers and tongues sliding in and out of her holes, and Seth reaching down to massage her breasts. It was only too soon that she felt her orgasm building up and overtake her. “Fuck.” was all she could manage to let out when it had passed.

*Ms. Callahan/Kevin*

Kevin came forward as Ms. Callahan took her position, “Are you ready?” she asked, spreading her legs and giving him a seductive smile.

“Hell yea.” he said, not quite as confidently as he intended but still making his point.

Kevin leaned down and Ms. Callahan pulled him up close and kissed him, pushing her tongue into her student’s mouth, then breaking the kiss to guide him down to her breasts. With a hand on one breast and his mouth on the other he sucked and fondled his teacher’s luscious boobs until she guided him down further.

Finally he was down at her pussy. The smell of her arousal was thick in the air, having already climaxed once that morning.

“There you go Kevin, lick my pussy just like that.” she encouraged as he focused on her clit. He devoured his teacher’s hot cunt while she moaned in pleasure – she knew exactly how to make him feel like he was doing well.

“Yea, just like that, fuck me with your tongue just like that…” she continued. He slipped his fingers into her pussy and fingerfucked her for a bit, and once his fingers were sufficiently lubed he shifted down and pressed his index finger into her tight asshole. She smiled down at him, “Oh yea, you want to fingerfuck my ass, yea, fingerfuck your teacher’s asshole.”

“Yea I wanna fingerfuck your asshole.” Kevin said getting into it, “Fingerfuck your asshole while I eat your sweet pussy. You like having your student eat your pussy.” he said smiling up at her.

“Hell yea I do.” she said winking back.

“Bet you’d like your student to eat your ass too.” he said back, “Why don’t you spread your ass for me like a good girl.”

Ms. Callahan had to admit this was all kinda hot. She admired her student’s assertiveness. Shifting over to her desk she rose and leaned over it onto her elbows, reaching back with one hand to open herself to her student.

Kevin moved behind her on his knees. He smacked his hands onto each of her asscheeks, “Yea, you like having your ass slapped slut…” he was really getting into the dirty talk now.

He worried for a moment if he’d gone too far, calling his teacher a slut in front of the class, until she responded, “Yea, tonguefuck my slutty asshole. Make your teacher cum…”

Kevin moved in and went to town on her gorgeous butt, one hand fingerfucking her cunt while she moaned things like “Yea, lick that ass… eat me just like that” and one of her hands went down to rub her clit. She had to admit she was enjoying it all more than she expected, afterall, she hadn’t expected to be fully eaten out by one of her students, to have his young tongue pushing into her holes, this wasn’t something they train you for in college. The plan had been to just partner with her coworker, to demonstrate with him then let the students practice with each other, but this was definitely nice too, so nice… so naughty… She concentrated on that thought until it moved her over the edge and her body shivered as her second orgasm of the day trickled through her.

She turned around and pulled him close and kissed him, then smiled and regained her teacherly composure, “Alright, very good. You’ve all done very well in your oral sex practice, and now it’s time to move on past foreplay to actual sex.”

The class responded with a mixture of “hell yea”s, giggles, gasps, and shocked silences from the few who even after everything they’d done so far didn’t think they’d actually be having sex.

Still swimming in the aura of her recent climax Ms. Callahan readied herself to get fucked by her coworker, “Pay attention now, Mr. Francis and I will be demonstrating standard intercourse.”

[To Be Continued…]

*{For the comments again, who’s your favorite couple? Still the same or changed?}*

Source: reddit.com/r/eroticliterature/comments/elc2c0/practical_sexed_ch_5_mf_oral_incest