Erm, I've never actually been caught. I said in a previous thread about having sex on top of an unmuted Xbox mic with a few friends at the other end, but that's about the most of it. We can be goddamned sneaky though. We've had sex in a room with both of her brothers and no one noticed, and I've felt her up while we were playing video games with some of her friends... Hell, she gave me the beginnings of a hand job with her parents sitting next to us on the couch (large quilts are awesome, by the way). The first time I got to second base was sitting on the couch while her brothers played Halo. Still haven't ever been caught. In fact, I wouldn't be the least bit surprised if her mom still thought we were virgins (my mom found a pack of condoms pretty early on, so I don't think she's under that notion).
OctoH said:
Also, my roommate in subsequent years would have sex with me still in the room. Honestly, I didn't care as long as they were not loud enough to bother me with my headphones in. I always had to resist the urge to pop a few brews and say "Cheers!" to them.
Heh, my roommate did that once while I was watching an episode of BSG. I ignored it while it was going on, but as soon as they were done I grabbed a beer from the fridge and tossed it to them. He laughed for about ten minutes, she made me leave while she got dressed. Not that I didn't see her naked in the reflection on my computer... I deliberately turned the screen after that. Watching naked girls is awesome, except when they're having sex with your roommate. Then it gets awkward.
He would later go on to have sex with other girlfriends on the bottom bunk while I was on the top one. I would make a comment every time afterwards (a couple times I gave him high fives, until once he said I might not want to do that. Stopped after that time.)