look up any word, like bukkake:
 
1.
A vulgar, but entertaining, idiom used for describing the act of vaginal copulation. Derived from the slightly more vulgar expression "crush piss box"
Son, if the third base coach waving you in, go crush box.
by DTP4L4L March 23, 2010
 
2.
To have sex or get laid
Did you crush box last night?
by lockdown77 November 13, 2008