A math student who used to come to the university on foot every
day arrives one day on a fancy new bicycle. "Where did you get
the bike from?" his friends want to know. "It's a `thank you'
present", he explains, "from that freshman girl I've been tutoring.
But the story is kind of weird..." "Tell us!" "Well", he starts,
"yesterday she called me on the phone and told me that she had
passed her math final and that she wanted to drop by to thank me
in person. As usual, she arrived at my place riding her bicycle. But
when I had let her in, she suddenly took all her clothes off, lay
down on my bed, smiled at me, and said: `You can get from me
whatever you desire!'" One of his friends remarks: "You made a
really smart choice when you took the bicycle." "Yeah", another
friend adds, "just imagine how silly you would have looked in a
girl's clothes - and they wouldn't have fit you anyway!"