look up any word, like half chub:
 
1.
sex
penis=jack, vagina=box
after the party i went over to jill's and we stayed up all night playing jack in the box
by jojo548 November 29, 2008
23 16
 
2.
Jacking Off
The Act Of Jacking Off While Think Of A Male Friend.
Kyle Was Playing Jack In The Box While Thinking Of Dave!
by Claudacious September 10, 2006
2 7