Let's all be honest with ourselves, real sex rarely ever goes as smoothly as it does in the pornos. Nobody is perfect 100% of the time. It's not uncommon to fuck up at fucking.
Share your sex fails here. Hell, it doesn't even have to be a sex fail. It can just be something funny or awkward that happened to you or someone else that involves sex.
I'll start us off with a story of gay oral gone horribly wrong. I'll use a spoiler tag. I suggest you do as well.
About 8 months ago I was giving this guy head. I started with licking and then went only about 3 inches down. He began to let his dominant instinct and impatience get the best of him, so he put his hand on the back of my head and shoved it down to get his whole cock in my mouth. There's a reason that I don't deepthroat; I have a terribly oversensitive gag reflex. He slammed my uvula hard and I vomited all over his junk. We never had sex again.
Here's another one in which I learned the dude I was having sex with (a different guy) was a total moron.
I was taking it in the ass because it was my turn to sub. When he climaxed I felt a gush of warmth and I was thinking "Hold on, I'm not supposed to be feeling that." So I told him "Dude, I think your condom broke." And he had this terrified look on his face. He said "Oh fuck! I'm not ready to be a father! I still have car payments due!" After I got over that random bout of stupid, I asked him how long he had that condom in his wallet. He said four months. I ditched him.
I look forward to what you have to share.
Updated by Clawstripe