When pounding the vagina at a high rate of speed, you miss the vagina and jab the asshole by mistake.
"Hillary, why are you walking like a duck"? "Uhhg, that asshole from the bar last night gave me a starfish surprise".
by Ben Fugin Cho Mamma July 08, 2012
1 more definition
When during the course of sex you slip your member into your partners ass without mentioning it first.
I was doin her doggy style last night and slipped her the old starfish surprise. Man she went wild.
by Gators #1 September 16, 2009