I've been flying 13yrs and have lost count of the of the amount of flight/cabin crew who by day go on about how much they love there boyfriends/girlfriends/wife. Then by night with a few drinks inside them they end up playing hide the sausage with another crew member.
It happens a hell of a lot. I would say that I see it happen once a month.
I've also known married crew with kids who are gay on nightstops.