I was watching a show with some guys I know where there was a line about a guy being really good in bed, how he can last up to 12 minutes. I laughed. The guys were all like, what? 12 minutes is good, right? My experience (a handful of different partners, not a lot) is that most guys can go at least 10 minutes, but some can go for hours. 20 minutes is about perfect for me, though.
So, not including foreplay...
Guys: how long can you last?
Girls: how long do you think is about right/average?
I'm curious to see if the answers vary a lot.