"Small boy and the dead Frog" joke

So a ten-year old kid walks into a brothel dragging a dead frog on a
leash behind him. He goes up to the madam and says, "I'd like a lady
for the evening, please."
The madam looks down an him and says, "Sorry, Kid, you're too young."
So, the kid reaches into his wallet and pulls out a hundred
bucks. He says a bit more forcefully, "I'd like a lady for the
evening, PLEASE."
The madam, never passing up a chance to make money, replies, "OK,
Kid. What's your pleasure?"
The young man looks back at the dead frog and says, "She's gotta have
an active, scorching case of herpes."
The madam is offended. "Look, Kid, all my girls are clean."
The boy reaches back into his wallet and pulls out another fifty
bucks. "I want a dirty lady."
"OK. Go upstairs, first door on your left. I'll send her in."
So about 45 minutes later, the kid comes out, happy as a clam, still
dragging that dead frog behind him. He's just about to leave when the
madam stops him. "Hey Kid, Come here... Why is it that a young boy like
you would want to a prostitute with herpes?"
"It's like this," says the kid, "When I get home tonight, my
babysitter's going to be there. I'll do her, and she'll get herpes.
About 10: 00 my mom and dad get home. My dad will take the babysitter
back to her place, screw her, and he'll have herpes. Then Dad will
come home and make love to my mom. At 8: 00 tomorrow morning, my dad
leaves for work. And at 9: 30, the milkman shows up. And HE'S THE
BASTARD WHO KILLED MY FROG!"