Teenage boy can't figure out how his friend gets laid all the time -- but he doesn't

He asks his friend how he does it. The friend whispers, "I'll tell you, but keep it a secret." The teenage boy excitedly agrees.

"All you have to do is, before you go to the beach, put a big potato down in your bathing suit. The girls will swarm you in no time."

The teenage boy does as instructed, but instead, the girls see him, scream and run away.

"What did I do wrong?" the teenage boy asks his friend. The friend looks him over and shakes his head. "Christ, man. You're supposed to put it down the FRONT."