She wins

You do your best, but the girl beats you. Only a couple of seconds before you, she arrives at the beach, and pulls herself out of the water, out of breath but laughing.
"Yes! That was fun. Sucks for you though."
You sigh, although it was fun, you really have no way to come home now. Then you get a new idea.
"How about" you begin, "We play another game."
"You´re really digging yourself in deep." The girl laughs, but hears you out.
"Same stakes. If i win I get my clothes and your panties, if I loose, you keep them."
"But I already have them, whats in it for me?"
You smile. "The game itself."
The girl tilts her head and looks at you. "I´m listening."
"If I make you cum in 5 minutes or less I win. If I dont, you win, and can use me to cum however you want until you do cum."
The girl gets up and shakes your hand. "Deal."