I thought of this last night, but I have not had time to try it. Still thought I would share it with you guys to see how you feel about it.
Me -I read something the other day in National Geographic. (or something similar, try to DHV that you read something else then just these forums

)
She -What?
Me -Give me your hands, (hold her hands)
Me -Did you know that the human body produces 20% more heat when two persons of the opposite sex are in contact with each other. That is why it is so comfortable to sleep next to another person.
She -for real?
Me - (squeezing the hand) Yes and did you know that if the two persons are attracted to each other the body produces 30% more heat then it would if it was alone.
If you are in a club a good chance would be that her hands are reall warm already but by the end of this you could neg her with something like
Me -Ow I think you are liking me a bit to much your hands are all sweaty. (let go of her hands)