Quoting K.MarieAnnette:" SO has slipped twice. it really was an accident, though... it's easy to do. lol. he was really upset ... [snip!] ... doing was saying "are you ok? are you ok?" i like anal sex... i just don't like a random hard thrust i wasn't expecting. lol."
Only one guy has ever accidentally slipped with me.. and he was really small, so it actually didn't hurt enough to piss me off (I was also drunk).. but everyone else I've been with has been too big to accidentally slip.. even average size is too big to do that.. they might accidentally hit the wrong target, but its not going to just slip in without effort, I don't care how slippery things are down there.. lol.. just not gonna happen without a conscious attempt..