There's this guy who decides to send his 16 year old son to a prostitute
to become properly initiated into sex. The prostitute takes him to the
bedroom and starts taking him through various routines, straight sex,
back, front, oral, anal, etc. Finally, she says "It's time to try some 69"
So they get into position and as soon as they get started she breaks
wind. The boy gets up and says, "God, how gross!" The prostitutue
apologies, says "Let's try it again". So they get into position, get
underway and she lets go again. This time the boy jumps up, runs to the
phone, calls his dad and says, "Pop, I don't think I can do this 67 more
times!".