So there's this dermatologist, ya see...

And he goes in to work one day, and his first patient comes in and says, "Doctor, you've got to help me. My boyfriend refuses to take off his letter sweater when we make love, and now I have this horrible rash." She takes off her shirt, and sure enough, there's a big red itchy rash in the form of an H on her chest.
The doctor says, "This is interesting, I've never seen anything quite like it before. I wonder why it occured in such an unusual shape."
"He goes to Harvard," she says.
"Ah, that would explain it," he says. He prescribes some calamine lotion and sends her on her way."
The next patient comes in and says, "Doctor, I hope you can help me with this rash. It's a little embarrassing, but it's driving me crazy."
She takes off her shirt, and displays a big, itchy, red rash in the shape of a Y. The doctor raises his eyebrows. "It's my boyfriend," she explains.
"He goes to Yale, and is so into his new letter sweater that he never takes it off, even when we're making love. Is there anything you can do?"
The doctor prescribes calamine lotion and sends patient number 2 on her way. The third patient comes in and says, "Doctor, you've got to help me!" She takes off her shirt, and there on her chest is a big, itchy, red rash in the shape of an M.
"Don't tell me," says the doctor. "Your boyfriend goes to MIT, and refuses to take off his letter sweater when you make love."
The patient looks at him with surprise. "Close," she says. "My girlfriend goes to Wellesley."