I've heard of bachelor parties. Always thought it was stupid concept. If you really want to get married, why act like your last day single is a time to get drunk and fool around with dancing girls or escorts? It just doesn't make sense.
Heard of the bachelorette parties. A lot of them may be innocent, but I've read stories by male dancers where they ended up screwing the bride after getting partially blown by the other girls. Of course, such stories get overblown.
I've only seen one such 'party', a bachelorette party showed up at a karaoke pub, a bunch of drunk girls having fun. I was singing a song, and one of the women said "that guy needs a blowjob!" No hanky panky happened, but obviously it was a sexually charged, fun loving group.