Rob staggers into the shower. He notices that his penis is bright orange. He feels normal, but he's concerned and goes to the doctor.
After a thorough examination, the doctor says, "You seem to be fine and all of the tests are normal. Did you do anything out of the ordinary over the weekend?"
Rob says, "No. All I did was stay home, watch porno movies and eat Cheetos."
Obviously he had been masturbating.