Occurs when an unexpected guest knocks on your bedroom door when you are masturbating and about to orgasm, and you open the door and ejaculate on them, shouting "Surprise Party!" Common in college dormitories.
I knocked on my neighbor's door to ask him if I could borrow his scissors, and to my horror he appeared at the door completely naked with his hand on his penis and promptly ejaculated in my eye, shouting, "Surprise Party!"
During intercourse, oral sex, or mutual masturbation, the male ,upon reaching his climax, proceeds to ejaculate upon the torso of his partner. At this point the male tosses a handful of confetti all over his partner and yells "Surprise!"
Wow, that was fantastic, your sister will be scraping the remnants of that surprise party off of her chest for hours!
When a lot of people you don't know show up at your house because they heard you were having a party.
Person #1: Dude, last night was such a surprise party!
Person #2: I know! Where the fuck did all those people come from?
MUST BE DONE WITH LIGHTS OFF! When a male pretends to have penetrated a female's vagina with his penis but in fact has inserted a life-like dildo (works best from behind). He proceeds to fake intercourse for a period of time, using the dildo all the while, and suddenly, falls off the bed with yell while leaving the dildo deep in the vagina. The male then turns back on the lights and yells surprise!
I threw quite a surprise party with your mom last night!