Ok, I suppose I can give a bit of backstory, and perhaps explain my thought process.

The night before I had run in to said female friend after not seeing her for two or three years. Back in high school we fooled around a bit, we stayed in touch in college, but from my senior year on, not so much. She was looking great, I look way better than I did back then, and we were just hanging out for a bit, talking about mundane shit like smoking grass and where we party, etc.

The next night (last night) she texts me and says she has a proposition. I was drinking and smoking with some friends at the time, and was pretty excited because I figured I'd be getting some action. So, she calls me shortly after and asks if I want to fuck her. I immediately say yes. Then she goes on to explain about her boyfriend watching. I pump the brakes a bit. Tell her I'll think about it, and hang up. I hash it over with my two buddies (who also went to high school with her) and they both decide I need to do it. They eventually leave, as it's getting late, and I'm left smoking a bowl by myself.

She keeps sending me text messages trying to warm me up to the idea (and that's about the time I asked all of you fine people on reddit). Somewhere around this time while doing the dishes and dancing, I drop my piece. It shatters all over the kitchen floor, irreparable. I remember that the girl in question has an impressive collection of smoking devices, and primo product. So, I figure I'll at least go over there, smoke some grass, have a few beers, and at the very least just hang out.

Two blocks and a right turn later, I'm at her place hanging out. I meet her boyfriend for the first time, he seems alright. A bit of a wimp, but alright. As the three of us smoke more and more, me and the boyfriend really hit it off. Like, he's a really rad dude. Our interests are shockingly similar, and the man can hold a conversation. All the while, the girl friend keeps pouring us shots, making sure we have fresh beers, and loading bowls.

She steps away for a bit, and gives us two some time to talk. And he just outright explains that he wants me to do her. We agree that she's incredibly sexy, and who wouldn't want to? To be honest, the conversation about what was actually to happen was very brief. Maybe 90 seconds of talking, and we made our way inside.

Quite simply, after meeting the boyfriend and just hanging out with the couple for a few hours, I just go really comfortable with them. They kept me well medicated with lots of tequila, lots of grass, and a bit of Xanax (all of which definitely helped make things more comfortable). That isn't to say that I wasn't lucid about what was going on, nor was I making those decisions that in the morning you think "FUCK! Shouldn't've done that!" I was just intoxicated enough to not have any hangups or anxiety over it.

The experience itself was pretty great. The sex was phenomenal, and I was allowed to do whatever I wanted. The only caveat was that every now and then the boyfriend would tell either her or me what he wanted next, and we'd oblige for a bit, and then get back to what we were doing.

Also of note: It wasn't a rule or anything, but there was no kissing of any kind. Plenty of biting, but no kissing. Interesting how that just happened. I suppose it's something of an intimacy thing.