How my girlfriend taught her sister how to suck dick [Str8] [MFF] [oral] [lesson]

My girlfriend’s (let’s call her Sam) family has always been open with sex and nudity in general. She would tell me stories on how they would talk about in a mature way while eating dinner, about how her parents would lecture them on contraceptives and STDs, etc…

When Sam and I became a couple, all this very open discussion of sex was a hard pill to swallow (haha) but I eventually learned and was even thankful since my family practically never discusses it at all. We would openly describe in *extreme detail* about our fantasies and since then, I never left their home without cumming at least twice.

Fast forward a couple of months, I was on my last semester for college and she was on her second year (since she decided to shift courses). Since I was working on my undergrad thesis then, I went to her place because (1) its very close to a public library and (2) she had a study room that I would use if I needed the peace and quiet.

2 hours in, I finally finished editing and decided to head to the kitchen for some food. When I got to the ground floor, I found Sam talking with her younger sister (let’s call her Annie) on the couch in the living room. By this point, I was rather close with Annie; we would eat dinner together, help each other with our studies (since we studied the same program but in different schools) and occasionally shop together so I decided that maybe I could help whatever it is she needed.

“Hey. You done?” Sam asked.

“For now. Problem?” I asked Annie.

“It’s nothing.”

“Don’t lie. You’ve been like this since yesterday.” Sam told her.

“Because it’s not right to ask you two.”

“Why?” Sam turns to me. “You wanna help her?”

“Uh sure but what about?”

The sweatpants I wore then were untied so it took only one swift movement until my entire lower body was visible. I immediately covered flaccid penis surrounded by trimmed pubic hair (Sam and I have kinks for those) while looking at Annie.

“We’ve fucked.” Sam said with a straight face.

“How about her?”

“Relax. She wants to learn how to suck.”

“If only you two agree and it won’t affect your relationship.”

“Seriously?”

Sam looked serious with what she said while Annie looked kinda conflicted but she looked directly at my genitals. I knew they were open to sex but this was a whole ‘nother level. Eventually, I accepted and lowered my hands.

“Is he a grower?” Annie asked.

“Mhm. Goes from 2 inches to 6.”

She grabbed Annie’s hand and ran it around my dick before she grabbed it herself and started stroking. When it was a little bit hard, Sam put it in her mouth and started sucking, moving her tongue in a circular motion around the head.

“The head is sensitive so be careful.” She said before handing it back.

Annie’s skills were nowhere near as good as Sam’s. It was a bit toothy, her tongue was all over the place, and it was hard for her to maintain a vacuum. Sam kept on giving pointers as I gave my feedback but I eventually started to go soft. I told my girlfriend as much so she took back my dick and made it hard again. We repeated this around 3 times, all the while Annie slowly getting down how to give a good blowjob. When the head started to turn red, Sam grinned at both of us.

“Let’s continue this in her room.”

She grabbed my sweatpants and underwear that lay on the floor as we headed back upstairs. When we got there, Sam took my top off as well, making me officially naked in her sister’s room. As the two girls began to strip, I decided to help out my girlfriend by removing her bra for her. Her tits are not big in the slightest, being only A cups (I also prefer small tits than big ones so win-win) and reaching down and feeling her trimmed pubic hair with my middle finger, the two of us sharing a kiss as I did.

I also helped Annie remove her clothes. Her tits were just a tad bigger than Sam’s but they were still A cups as well. Her pubic hair was also overgrown, obviously growing for a long time.

“Next time, I’ll teach you to shave.”

This was the first time I saw Annie naked so the sight got my dick a lot harder than what I expected. Sam saw my dick move up and down so she grabbed it, got on her knees, and started sucking.

“Hey I thought you were letting her practice.” I said.

“Just a minute. You’re pulsing.”

After the minute had passed, we got on the bed and continued the cycle. Sam makes it hard, Annie practices, I give feedback. Though this time, I had Annie suck me in a 69. This has been going on for nearly 40 minutes now so I was getting relatively close to cumming so I ate out Annie as a distraction. She was still a virgin so the sensation made her moan a couple of times. I felt her legs lock up my head as I thrust my tongue deeper and deeper into her. Her legs started to stiffen the more I did which made her go a little harder with my dick.

After nearly 50 minutes, my dick was so sensitive that a rogue lick on the head could make me cum. Sam knew my tells by then so she told Annie to stop.

“He’s gonna cum.”

“Yeah I think I can taste the precum. Do you spit or swallow?”

“Spit most of the time. I like the cum running down my chin.” Sam said as she carefully stroked my shaft. “You have him cum where you want.”

“Then I’ll try swallowing.”

“You ready?” Sam asked me.

“Sure.”

I felt Annie’s tongue a lot more now than when we started and her vacuum felt a lot better. My toes curled, my legs stiffened, and I fondled her tits as it happened: I spewed my load into her mouth. I could still feel her tongue massaging the head, though now even more slippery with my cum. A moment later, I heard a cough and felt my hot cum run down my dick.

“Sorry. Don’t think I can swallow it yet.”

“That’s fine. Sometimes it needs practice.” Sam looked at me. “So, how was she?”

“Honestly? 5/10.”

“Really? A 5?” Annie asked as she got off me.

“Yeah.”

“Tell you what.” Sam spoke. “Practice on him all you want.”

“No.” Her sister said.

“It’s fine. You can do it by yourselves or with me but it’s totally fine as long as you two don’t fuck.”

“You sure about this?” I asked Sam. “Knowing your sister is sucking me off…”

“Yeah.”

No second thoughts. No hesitation. Just a quick and unmoving “yes”. I looked at Annie and saw that she had a good time, evident by the cumstains still dripped from the corner of her mouth that she wiped off with her hand and part of her pubic hair sticking together because of my spit.

“You want to do this again?” I asked her.

“If it’s okay with you.”

“Then… sure.”

Sam grabbed her sister’s clothes and handed it to her. “Take a bath.”

“What about you two?”

Sam grinned at me with a fire in her eyes. “My room.”

​

**NOTE:** This is obviously not a 1:1 recreation because it happened a year ago BUT it stuck with me with just how… unexpected this all happened.

Source: reddit.com/r/sexystories/comments/kzqbst/how_my_girlfriend_taught_her_sister_how_to_suck