shitty surprise

This sexual act can only be performed once in a relationship. If done more than once, the subject should be subject to ridicule.
This act can only be performed if the subject is unaware. A Shitty Surprise is the act which when a woman is about to receive a mans ejaculation, the man makes her close her eyes, he then turns around and shits on her face.

Note: Explosive diarrhea works best!