n. When it comes time in a porn star's life, her ass dramatically sags, and the guys in the film slap it like a banjo.
"She was a pretty hot bitch, but now her ass is a busted trunk, and reeks of sardines."

"During the filming of 'Prom Night', Mercedes got a busted trunk."
by MMjr March 28, 2009
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When you forget something in the trunk of your car, so when you go get it you decide to bust a quick nut in your trunk no matter where you are.
Friend: Bro, what is that white shit in your trunk?
Me: I did a trunk bust this morning.
by Tony two timez January 22, 2018
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