I know i know...So what is it?
Okay i'll tell you.
Well, when a girl is on her...ahem...menstruation cycle (for all the dumb shits, her periods...) the male in the situation (it is possible he may not be a male) would proceed in sucking (thats right, sucking.) the period from the opening in the vagina from which it exits.
No, i did not make this up. Its real. And if you have done it, please go see a psychologist.
Jenny Slutface: "Oh Jimmy, i can't! I have my period!"
Jimmy Sickfuck: "Jenny! Lets do the Angry Red Dragon!"
Jenny Slutface: "Whats that?"
Jimmy Sickfuck: "Let me show you..."
Jenny Slutface: "Oh Jimmy, thats amazing! And now my period's only gonna go for one day!"
Jimmy Sickfuck: "Do you have a straw?"