I would (or do) regret sleeping with nearly anyone on my friends list.
There are a couple of exceptions, but honestly, that's kind of a creepy question to ask in an abstract way. "Try it and find out" is pretty much the only healthy response to that - there's a very real sense of "you don't get to see the cards if you don't put your chips on the table" when it comes to that topic.
Unless of course you're a guy, in which case it's the same response no matter WHO the hell you are. I'm not exactly sure what that response is, but I'm sure it wouldn't be a good one.