Little Billy is pulling a dead frog on a rope

... as he walks into a brothel. He walks up to the madam and says loudly and proudly, "I want to have sex with Monica."

The madam says, "but you're just a boy, you can't be here."

Billy pulls out $3000 dollars and says, "I am a paying customer, and I want to have sex with Monica."

The madam looks at the cash and thinks that they could use it. "Okay, little boy. But why do you want to have sex with Monica? There are a lot of women here?"

Billy replies, "I heard she has chlamydia."

The madam starts laughing and says, "why in the world would you want to knowingly have sex with someone who has chlamydia?"

Billy takes a couple steps closer, he says "well you see, my parents are going out to dinner tonight and I'm going to have sex with my babysitter. I know that when my daddy takes her home, he's going to have sex with the babysitter. Then tomorrow, he'll have sex with my mom, and then the next day, my mom will have sex with the mailman, and he's the son of a bitch who ran over my frog!"