would smash
When, given the perfect situation in which no one would know and there would be no negative repercussions whatsoever, you would have sex with a given person.
Guy 1: Dude, this girl's so hot.
Guy 2: Yeah, would smash.
Guy 2: Yeah, would smash.
Would smash
A showing of endearment, commonly meaning "that's cute!". This is normally addressed to things you find adorable like dogs or little girls.
A: This is a picture of me in 3rd grade,
B: Awwww would smash!
B: Awwww would smash!