The moldy residue that builds up on your penis after having unprotected sex with several prostitutes. If not properly cleaned right away it has been scientifically proven to develop new strands of bacteria that modern medicine is unable to cure or properly treat.
Person A: Hey bro, what did you put on my toast?
Person B: I rubbed my dick on it, it's hooker taint.
Person A: Wow, I can't believe it's not butter!