The sexual act, in order, where one ejaculates on their own penis, sticks it in their partner's ass and gets it covered in poop, and then stick the whole thing in his girl's vagina when she is on her period. each forming the ice cream, chocolate sauce, and cherry on top, respectively. The girl will then suck it all off, including his nuts, since no sundae is complete without nuts.
Did you hear what happened to Adam? He and Jamie tried a Sundae Surprise, now she has a UTI and he has shitdick.
by When_the_Hymen_Breaks May 05, 2015
When a girl is giving you head, cum on her face and then throw sprinkles on to her cum covered face and scream sundae surprise!
by Dirty Dahm September 15, 2011