December 3, 2009, is a day that will live in tabloid infamy: That’s when “Jersey Shore” premiered on MTV with a sonic fist pump.

The reality series — set in the resort town of Seaside Heights, NJ — followed eight strangers who lived together in a summer share house and drank and tanned to excess. The show turned the phrase “gym, tan, laundry” (“GTL”) into a lifestyle. It also caught criticism for its portrayal of Italian-Americans as party-hearty “guidos.”

After six seasons, it wrapped in 2012 — but now, the cast has reunited for “Jersey Shore Family Vacation,” a limited series debuting Thursday on MTV.

Here, the stars of “Jersey Shore” — Snooki, The Situation and the rest — reveal just how wild life was off camera, too.

SallyAnn Salsano, Executive Producer and Creator: “I got a call from [an executive at VH1] named Shelly Tatro, who said, ‘I’m calling you because you’re the biggest guido I know. We wanna do this guido competition show.’ I felt like that wouldn’t work because we were talking about tanning contests, fist-pumping contests — I’m like, ‘It’s almost like you’re making a mockery out of it.’

She said, ‘I’m going to send you a tape of these two guys and this is the archetype we’re talking about.’ The Situation was one of those guys.”

Mike “The Situation” Sorrentino, cast member: “[The show] was going to be called ‘Guidos.’ I was one of the original people and that was probably one of the reasons that I was pretty cocky in the first season.”

Salsano: “I [used to go] to the Jersey Shore [for the summer]. Back then, there was no . . . Facebook. [You’d] go to a realtor’s office, see a picture of a house and they’d say, ‘There are four spots left’ — and you’d hope there [were] single guys. And every summer . . . there was so much drama. So I went back to [VH1] and said if you had a regular Shore house, this is what it would look like. They gave us money to cast the show and we scoured everywhere. We went to their natural habitats. We went to the clubs.”

Vinny Guadagnino, cast member: “The application called for the biggest, muscly, orange-skin, spiky-hair guidos in the area. I took offense to that. I look nothing like that. So I filled out the application almost as a joke. I said, ‘Hey this is what a real person who goes to the Jersey Shore looks like. I’m not muscular, I’m not orange. I go to school. I’m close with my family.’ ”

Salsano: “Vinny’s casting tape was like, ‘I’m not a guido’ — and I’m like, ‘You’re the biggest guido.’ There are different types.”

Paul “DJ Pauly D” DelVecchio, cast member: “I got a message on Myspace that said, ‘We like your look. We’re doing a television show.’ I was making fun of the message, saying it’s probably fake, but I left my number. [The producers] wanted to film a day in my life.”

Salsano: “When I met Pauly D, I was like, ‘This guy can’t be real.’ I sent someone back to his house for a second time because I was like, ‘There’s no way.’ ”

Nicole “Snooki” Polizzi, cast member: “I went [into the casting interview] drunk. I was on my way down the Shore, so . . . I ran into the bar, talked to them for a bit, and ran out. Honestly I don’t remember the first interview, but I am pretty sure I killed it.”

Ronnie Ortiz-Magro, cast member who was discovered at the Belmar, NJ, club D’Jais: “[The producer] was like, ‘What do you do when you walk into the club?’ I said I take my shirt off. She asked me to take my shirt off, flex my muscles, fist pump and do pushups. I was like, ‘Is this [show] going to be about the top 10 dumbest people in America?’ ”

Once the cast was assembled in August 2009, all eight moved into a Seaside Heights shore house outfitted with cameras. For the month of filming, they were required to surrender their cellphones and prohibited from watching television in the house. It was a recipe for drama.

Ortiz-Magro: “You had nothing to distract you. A lot of us [would] lock ourselves in the bathroom for two hours — a piece of sanity to get away from the cameras.”

Polizzi: “You get bored because you have nothing to do but just look at each other and talk. I think it definitely made us want to drink — and that was the point.”

DelVecchio: “There’s cameras 24/7. So if we bring girls back from the clubs, it’s on camera. I thought there was no way girls [would] wanna hook up on camera — they had to give producers their phones, sign paperwork. But they didn’t care. I guess there’s tons of sex tapes [from the show] out there.”

Although the series was originally sold to VH1, Salsano recalled that “MTV was looking for something to make a little bit of noise. We changed the name from ‘Guidos’ to ‘Jersey Shore’ about a month before it aired.” Still, Italian-American groups were incensed over what they viewed as a negative portrayal.

Salsano: “The Italian-American groups went mental. [We were afraid the] show was going to get pulled. Advertisers were pulling out. Domino’s [Pizza] pulled out. It wasn’t like we were out to ruin the guido. We’re celebrating it.”

Polizzi: “I thought it was great publicity for the show. I’m Chilean, so it didn’t bother me — I’m not Italian. I just think [the haters] were very dramatic.”

DelVecchio: “I had a tanning bed in my apartment, an Italian flag on my ceiling and tattoos and hair gel. I’ve always lived the guido lifestyle and looked at it as a positive. I was like, ‘Why are these people ragging on us? What did we do wrong?’ . . . I never said I was representing anyone other than myself, so I was mad. Now I want to send [all the offended groups] Champagne, because [people started watching] just to see what the controversy was. Now I thank them for the ratings.”

The show was an immediate pop-culture phenomenon and went on to set records for MTV. Cast members went from unknowns to celebrities overnight — they were mobbed at restaurants and clubs and even attracted A-list fans.

Guadagnino: “The first night we went out in Los Angeles, we met Leonardo DiCaprio. Not only did we meet him, he was reciting lines from the show back to us. I remember he was hooking me up with girls. He raised his glass and tipped it to me like he does in ‘The Great Gatsby.’ We’re just regular dumb kids from the East Coast. In the blink of an eye, we’re hanging out with Leo.”

Polizzi: “[At the MTV Video Music Awards,] Beyoncé came up to us and kissed us on the cheeks and said, ‘I love your show.’ I was like, ‘I can retire now.’ ”

One plotline that really shaped the dynamic of the group was the love story between Ortiz-Magro and Sammi “Sweetheart” Giancola. Although, it could’ve been the story of Giancola and almost anyone else.

Guadagnino: “Sammi, the first night, she first kissed Mike and then she ended up moving to Ronnie. It was a big love triangle in the beginning. I remember the first night she gave me like a flirty kiss on the cheek. She was going around, planting her seed with each dude. I think she did it to Pauly, too. Mike ended up taking the bait [but then] Ronnie obviously swooped in — and that’s all she wrote.”

Sorrentino: “She was one of the girls I thought was attractive. Eventually, we did hook up and — I don’t know what happened, but in the club one night she hooked up with Ronnie. I didn’t blink an eye. He stayed on that train for eight years. They would fight like cats and dogs. I guess you could say that Ron had taken the bullet for me.”

The volatile on-and-off-again couple became known for their jealousy-fueled arguments, montages of which are readily available on YouTube — including the time Sammi punched Ronnie and he trashed her room and moved her bed out while she was still in it.

DelVecchio: “Maybe that’s the reason I don’t have a relationship to this day — because of their relationship. It took a toll on the house. As agonizing as it was to watch [on TV], living it was three times worse.”

Ortiz-Magro: “When Sam and I [went outside] the house we never really fought. But being in the house affects you emotionally and physically. It’s a lot of pressure. Me and Sam don’t talk anymore. She’s got a boyfriend and is happy and chose not to do this [reunion] season. We want her to be happy.”

Sometimes, the theatrics spilled out of the house. Fellow Shore clubgoers picked fights with the cast and mocked them mercilessly, including the on-camera incident from Season 1 when Queens gym teacher Brad Ferro decked Snooki in the face during a night out at Beachcomber Bar & Grill.

Guadagnino: “Every time we went out the door, there’d be someone trying to fight us. We were guidos wearing glittery shirts.”

Polizzi: “[The night of the Beachcomber punch] I kept ordering shots . . . but [Ferro, a stranger] would grab them and give them to his friends. So, the fourth time he did it, I said, ‘C’mon dude, those are our shots.’ I guess that pissed him off because he punched me.”

Although MTV decided to pull the actual scene where Polizzi was punched, news of it brought swells of attention to the show — and created a bond among the cast.

DelVecchio: “You could say it made the house come closer together because we felt so bad for this girl.”

Guadagnino: “It was mayhem. We were all running around [after the punch], wanting to kill someone. We saw [Ferro’s] friends and they put their hands up and were like, ‘Dude, we’re sorry.’ They were just as shocked.”

Ferro was arrested and found guilty of simple assault; he was fined $500 and ordered to complete an anger-management course. While filming Season 3, Polizzi had her own brush with the law when she was arrested on the Seaside Heights boardwalk for disorderly conduct in the middle of the afternoon. She was issued a summons and released.

Polizzi: “That was fricking awesome. I’m actually so proud of that. I’m nervous for . . . my kids to see that one day, but I’m just gonna use it as, ‘Don’t do what Mommy did.’ ”

In 2011, then New Jersey Governor Chris Christie said “Jersey Shore” gave the state a bad name. Noting that many of the cast members were actually from New York, he told Governor Cuomo to “Take them back.”

Polizzi: Dude, you’re a politician. You should be doing something else besides fighting with a reality star. He hated us — which mind-boggles us because we made millions of dollars for [Seaside Heights].”

Christie declined an interview, saying he “respectfully will pass on discussing ‘Jersey Shore’ — ever.”

Salsano: “Season 1 we shot in Seaside, and then in Miami for Season 2. We came back to Seaside for Season 3 — and there were thousands of people lined up outside the house. They’d say, ‘I’m from Virginia’ or ‘I’m from Wisconsin.’ And it was so many families. Because of the show they were coming. It was really huge for travel, and all the local businesses would knock on the door and thank us.”

Deena Cortese, cast member who joined the show in Season 3 after original housemate Angelina Pivarnick was booted: “We were bringing in so much business, and we kinda cleaned the place up.”

Chris Vaz, Seaside Heights Borough Administrator: “Some, not all business owners will say they had good summers, but it hurt the reputation of the town. The problem with ‘Jersey Shore’ is how the town became another character in the show. We had no control over how that character was portrayed.”

When the town was approached in 2017 to film a similar type of reality show, officials declined.

Vaz: “The borough drafted a new filming permit. We have communicated that we don’t want to see those types of reality shows. In general, reality TV is dependent on conflict and drama and — in the case of ‘Jersey Shore’ — vulgarity. That’s not something we welcome.”

Still, the cast recognizes that conflict and drama is exactly what made audiences love — or love to hate — them.

Polizzi: “We’re the only reality show that’s real. We basically didn’t have any boundaries, and I guess we weren’t nervous to show our true selves. We don’t care if you’re judging us. We just say what we really [think] and how we feel. That’s why it worked.”