Paddy and Colleen were making passionate love in Paddy's mini van when
suddenly Colleen, being a bit on the kinky side, yells out "Oh big boy,
whip me, whip me!" Paddy, not wanting to pass up this unique
opportunity, obviously did not have any whips on hand, but in a flash of
inspiration, he opens the window, snaps the antenna off his van and
proceeds to whip Colleen until they both collapse in ecstasy.
About a week later, Colleen notices that the marks left by the whipping
are starting to fester a bit so she goes to the doctor. The doctor takes
one look at the wounds and asks, "Did you get these marks having sex?"
Colleen, a little embarrassed that she has slept with Paddy (let alone
that she allowed the kinky boy to whip her) eventually admits that, yes,
she did.
Nodding his head knowingly, the doctor exclaims, "I thought so, because
in all my years as a doctor, you've got the worst case of van aerial
disease that I've ever seen."
... master class "crack"! 
nice one Doc
