A nerdy college student always eats his lunch outside a lecture hall. There's another student, a young preppy guy, who also hangs there. This guy talks up the girls who go by, and he often gets their phone numbers. After weeks of watching, the nerd goes up to the preppy guy. He says, "How do you get all the girls to talk to you?"
Preppy guy is flattered. He says, "Well, my man, you gotta have style and humor. I'll sort of mumble to them as they go by, 'Tickle your ass with a feather.' And they'll usually ask what I just said, and I say, 'Typically nasty weather.' Chicks think that's funny, and, as you've seen, I usually get their contact information. You should try it some time."
The nerd goes back to his dorm room and thinks it over. About a week later he's outside the lecture hall and he sees an attractive young student coming his way. He goes up to her and says, "Hey, shove a feather up your butt!" She screws up her face and says, "What??" He says, "It looks like it's gonna fuckin' rain!"