The cast of the MTV series left their usual location of Seaside Heights, NJ for Florence to tape the fourth season of the reality show, which currently airs on Thursday nights.
Speaking on The Tonight Show with Jay Leno, Cortese said: "It was my first time out of the country without my parents or my close, close friends.
"I felt very lonely in Italy. A lot of them had boyfriends and I was like the single girl having a good time. It was hard to find guys out there because some of them didn't speak English, some of them hooked up with their sisters! It was hard to communicate."
Cortese went on to talk about her hook-ups with co-stars Pauly D and Snooki, which were both caught on camera and aired in past episodes.
"Me and Pauly are really close friends and we were both drunk and having a good time, we're both single, and we were like, 'let's make out, whatever, it's a good time'," she explained, in reference to their kiss in the first episode.
"And me and [Snooki] make out when we're drunk sometimes, it happens! Team meatballs! Meatball power! It was kind of stupid. The roommates were all being so lame and judgmental when they have seen it happen before! It was like, 'why are you surprised?'"
Jersey Shore continues Thursdays at 10pm on MTV.
> Jersey Shore recap: Where is my boyfriend?
> Jersey Shore recap: Snooki hits police car
Watch more of Deena Nicole Cortese talking to Jay Leno - and introducing herself to fellow guest Ed Helms - below: