sammi sweetheart

Before Ronnie Ortiz-Magro started messing around in Miami, he hooked up with some random girls in a Long Island club's bathroom, according to a clip played on 'Jersey Shore After Hours' (Thu., 11PM ET on MTV).

In the 'Jersey Shore' footage, Jenni "JWoww" Farley tells Ronnie's sometime-girlfriend Sammi "Sweetheart" Giancola to "go get checked" for STDs.

As JWoww explains it: "Ron told me ... he went to a club in Long Island and he actually smushed the girl in the bathroom, and then later that night went home to Sam." Sammi says, "I will kill him when he walks in that door!"

On 'Jersey Shore' (Thu., 10PM ET on MTV), Vinny says he keeps his mouth shut. And then he doesn't -- instead telling Jenni "JWoww" Farley that Angelina "Jolie" Pivarnick told a lie about her.

Jenni confronts Angelina and Sammi "Sweetheart" Giancola, who says she "doesn't give a [beep]." Jenni says, "Did you grow some balls all of a sudden?" Sammi responds: "I don't fight because I'm mature, I'm classy!" and then proceeds to scream and shout at her.

Jenni yells back, "Why don't you like me -- because I came to you as a woman and told you about your man?" -- referring to the anonymous note that told Sammi about Ronnie's cheating ways. Jenni shoves Sammi's head. Arms start flailing, and Sammi throws a punch.