It's a football letterman's jacket from State. You're starting there in the fall, and eventually, you'd have bought one, but it's a great present. You put it on, and frown, it's a couple sizes too big. You step over to the mirror to see how you look.
The jacket seems to get lighter and tighter as you wear it. You stare at your image in the mirror. The mirror seems to be sliding down the wall. No, you realize you're growing to fit the jacket. Your loose jeans are now skin tight and expose your calves slightly. They're like long board shorts now. You chuckle as you puff out your chest. The t-shirt you were wearing seems painted to your chest. You can see the ribbing of your six pack abs through the taut cotton cloth.
You grin and immediately take off for the park to meet your secret admirer who turned you into a muscled giant.