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!"