The amazing moment when one, who is usually engaging in foreplay with a woman while on top of her, tries to tug off her pants and she lifts her gluteus maximus to make said action easier. It is the closest thing to her sayin she wants sex. However, don't mistake this action as fully giving consent.
"I was making out with the girl I had been going out with for a little while, and when I reached for her pants, she gave me the butt lift. It was my happiest moment with her up till then."