From the SNL skit, Jizz In My Pants.
"When I ate that greape, i jizzed in my pants!"
"That chick made me J.I.M.P!!"
stands for Jizz In My Pants. used to describe something so awesome it makes you want to jizz in your pants.
dude he totally just jimped, now we are gonna need a clean up on isle 3!
Bob: Guess What?
Tom: What?
Bob: I just jimped.
Tom: ?
Bob: i just jizzed in my pants haha!
After she walked by i totally just j.i.m.p'd