So Marvin decides to go to the beach and he sees this guy, with chicks all around him.
He says to the lifeguard, "Gosh, lookit that guy, he's got all the luck, he gets more girls than you or I could ever imagine! How does he do it?"
The lifeguard looks at him and says, "Marvin, tomorrow, come back with a potato in your pants and see what happens."
Well, he does indeed this. However, everyone was laughing at him.
So Marvin goes to the lifeguard and says, "I did what you said. I put a potato in my pants, but now everyone is laughing at me. What are you trying to do to me?"
The lifeguard looks at him and says, "You were SUPPOSED to put it in the FRONT!"