Which Jersey Shore Castmate Partied With Lil Jon? (PHOTO)

Ronnie is all about his Ron Ron Juice these days, but in this throwback photo, he was getting low and chugging Crunk Juice with Lil Jon and NFL player Kassim Osgood.

When we saw this Instagram pic, we were a little surprised, but hey — Ronnie has a lot of famous friends!

Did you know it was him, or did we stump you? Tell us below, and then click here to play more Jersey Shore “Guess Who?”