'Jersey Shore' Sammi Sweetheart Filming With Cast in Florida After Show Return

Here's Sammi 'Sweetheart' Giancola filming with her "Jersey Shore" castmates ... the first time we've seen her back together with the group since her surprise return.

Sammi looks right at home in video obtained by TMZ ... getting back on the horse with Vinny, JWoww, Pauly D, Angelina, Deena and The Situation for the upcoming season of 'Family Vacation.'

Folks who were there tell us the cast was shooting scenes Tuesday night at Reggiano's restaurant in Celebration, Florida ... and the only one who seems to be missing was Snooki.

As you see, it appears to be a couple's outing for a birthday party ... complete with cake, candles and significant others -- unclear whose birthday it was.

It's interesting ... Sammi's date is a tattooed hunk with a striking resemblance to her reality TV ex, Ronnie Ortiz-Magro.

Remember ... Sammi and Ronnie have an extremely rocky history, and there's speculation she's finally back on the show in large part due to Ronnie moving on from the 'JS' life.

Sammi's return is a huge deal for fans of the MTV show, and it looks like she's happy to be back in the fold.