This one is hilarious:
One day a twelve year old walks into a house of
ill-repute dragging a dead frog on a string
behind him. He slaps a hundred dollar bill on the
counter and says, "I want one of your women."
The madam looks at him and says "Don't you think
you're a bit young for that?" He slaps another
hundred on the counter and says "I want one of
your women."
The madam says "Okay, have a seat, she'll be down
in about thirty minutes." He slaps another
hundred on the counter and says "She has to have
active herpes." The madam starts to sputter and
ask why, but he slaps another hundred on the
counter and says "Active herpes." She responds,
"Okay, have a seat- it'll be about five minutes."
Two minutes later, a woman comes out, they go
upstairs (dragging this dead frog) and do their
deal...
As he's leaving, the madam asks him, "Okay, why
did you want someone with active herpes?" The
twelve year old replies, "When I get home, I'm
going to sleep with the baby-sitter, and when mom
and dad get home, dad will take the baby-sitter
to her home and sleep with her on the way. Then,
when he gets back, he and mom are going to go
upstairs and do it. And tomorrow morning after
dad goes to work, the milkman will come in and
mom will sleep with him, and he's the bastard
that ran over my frog.
