[MF] My wife and I overheard my sister having sex and got so turned on

I’ll try to make a long story short. This originally started when my wife and I decided to have a very small get-together at our condo on New Year’s Eve 2020. We only invited two people: my sister and a friend of mine from work. Both had been COVID tested very recently, and we specifically chose them because my sister is single and lives alone, and we didn’t want her to be alone. And my friend is also single and lives alone, and he has some on-and-off issues with depression and anxiety; nothing too severe, but I feel bad for him because he’s a really nice, humble guy. He’s the shy introvert type who doesn’t have much luck or experience with women, so I thought it would be good for him to have a fun night over at our place without too many people to make him anxious.

The night turned out to be a blast. We were all drinking pretty pretty liberally, watching movies at first, then socializing and playing cards and listening to music, stuff like that. Everybody was enjoying each other’s company. The drinks were still flowing after midnight, and my friend was coming out of his shell. My wife and I both noticed an hour or two prior that there was chemistry building between him and my sister, and it was getting more and more obvious. A little later on at around 1:00 a.m., my sister approached my wife privately and said something about how she was pretty sure something might happen between her and our friend that night, and my wife wasn’t really surprised at all because she saw it unfolding a few hours prior.

My wife suggested that they should just stay at our place because they’d both had too many drinks to drive, and it was really cold that night where we live, and she would feel guilty having them take a taxi. My wife then approached me privately and asked if it would be ok if they stayed overnight and asked me if it would creep me out if they did, because there was a pretty good chance at that point that they would end up having sex. I was pretty damn tipsy at that point, and at the time the thought actually didn’t really bother me, so I said it would be okay. I didn’t want to send them out into the cold night either.

Our condo isn’t terribly big, and the spare/guest bedroom we have is right beside ours. So about 5 minutes after we all crashed, sure enough, the playful noises started coming through the wall. Then within about 10 minutes it was full on sex; bed springs and moaning and the whole production. I don’t know why, but I started getting that really excited naughty butterflies feeling in my stomach, like that feeling you get when something is erotic but weird/naughty at the same time. That’s the best way I can describe it. And I could tell it was getting my wife a bit riled up too.

So we ended up recording a little bit of it with my phone for a little while. Then we ended up having sex while we could hear them at the same time, and it was so weird but immensely hot at the same time. I was on top of my wife and could feel her entire body involuntarily trembling with excitement, and her breathing was rapid and shallow. I was trembling so hard and breathing rapidly too. The excitement and butterflies were so intense for me that I could only last about 40 seconds before I lost control, but I was still so excited that I could just keep going without stopping even for a moment, and I had a second orgasm about 5 minutes after that. My wife said that her butterflies were probably just as intense as mine were; she described it as her abdomen feeling like a cement mixer LOL. That’s a pretty apt description of how it felt for me too.

I feel absolutely no attraction towards my sister at all and have never had a sexual thought about her, but I still wonder if I’m some kind of a sick freak or perv. My wife assures me that I’m not and feels that the only reason it excites us both is because it’s so naughty and taboo and out of the ordinary.

This has happened a six more times since the initial incident on New Year’s Eve. My wife and I have started deliberately inviting the both of them over because we both get such a kinky rush out of knowing what’s going to happen. We both get really intense butterflies when we hear them, and the taboo excitement is such a thrill for us. My wife is convinced that my sister is getting a rush out of doing this too because for one thing, she keeps repeating it. The first time could’ve been considered a slip of judgement because she was tipsy and just wanted to get laid. But if she had been awkward about it after the fact, she wouldn’t keep doing it. My wife also pointed out how intensely her voice quivers and trembles when she’s moaning, and she thinks that’s an indicator that she’s also getting really intense butterflies from the taboo excitement like we do.

My wife and I love this so much now, and we want to keep it going for as long as we possibly can because we’ve never felt such intense excitement. The butterflies we get make our sex so passionate. We are even thinking of maybe inviting over another guy in the future too just to see if she would end up doing this with someone else. If she did, that would pretty much confirm that she finds this just as thrilling and exciting as we do if she was willing to spontaneously get laid by another person.

I actually posted about this [in this sub](https://www.reddit.com/r/overheardsex/comments/y09psa/my_wife_and_i_overheard_my_sister_having_sex/), and that post includes links to all the audio clips we have recorded of them (at the bottom of the post.)

Source: reddit.com/r/gonewildstories/comments/y4sobr/mf_my_wife_and_i_overheard_my_sister_having_sex