Purple Nurple
(Yeah Yeah Yeahs - Maps)

Coworker - I gotta go and pick up some stuff at the running room for the half marathon.
Me - New shoes?
Coworker - No, nipple band-aids.
Me - I didn't know you had to be concerned about purple nurples while running.
Coworker - Haha. No, no...when you run long distances, your nipples bleed.
Me - What the hell are you talking about?
Coworker - From chaffing on your shirt.
Me - You have got to be shitting me.
Coworker - I'm serious!

...and that's why I don't run long distances.