Three MIT undergrads are admiring the graduate assistant's new mountain bike. One asked "How did you afford such a nice bike as a graduate assistant?".
The GA says "I didn't buy it, some co-ed gave it to me."
All three undergrads: "Gave it to you?!?!"
Says the GA, "Sure. I'm walking through the quad on the way to the lab, and this co-ed rides up on this bike. She tears off her clothes and says "take what you want". I didn't think the clothes would fit."
Yup that's the one! Thanks!