A girl has a sleepover with 3 guys. Then her dad comes down and paints her vаginа purple. He tells the boys,"I'm going to sleep. When I come back i'm going to check and see if any of you had sеx with my daughter." An hour later, he wakes up and checks everybody. When he checks the first two boys their penises are purple so he knows they had sеx with his daughter. When he checks the last guy his diск is clean. The dad says "Good job."
When the third boy opens his mouth to say thanks, his mouth is purple!