smash your panties

Coitus between a male and female when the female is still wearing her panties, and they must be pulled aside for the man's penis to penetrate the vagina.

"Meet me in the back of the library, I'm gonna smash your panties" or "Man, you wouldn't believe it, but I smashed that chick's panties last night" or "I want to fuck you right now bitch. Don't worry about taking your panties off, I'm going to smash them"