by-catch

Too inadvertently woo the friend(s) of the girl/guy one is actually pursuing.

Bro: I've been trying to get on Hannah but I think her friend Emily likes me now.

Bra: Dude, she's not a bad by-catch.

cop blocked

When an officer of the law prevents someone from scoring sexually. Typically occurs when the sexual act in question is taking, or will take, place in a car.

I was about to get a BJ from Sarah in my car, but then the popo rolled up and cop blocked me.