Ex On The Beach 5 will see the return of both Gary and Jemma, and back when the show was filmed in April, the pair had slept with each other on the first night.
Looking back, Gary has now said he "regrets" bedding Jem, and admits: "I maybe shouldn't have done that."
Speaking to our friends over at Digital Spy, Gary explained: "You can't actually say you didn't want to do these things or whatever, but I definitely regret that first night."
At the time, reports had surfaced detailing Gary's night with Jemma during filming in Thailand and prompted Charlotte Crosby to call it quits with him. He and Charlotte had picked up their on/off romance and were trying to work out whether they had a future together.
Heading onto Ex On The Beach, Gaz actually admits that the show is a "test" for him to see if he is ready to commit to Charlotte and from the get go, Jem makes it clear she is after Gary.
She says: "Obviously, Gaz is looking unreal... ripped, shredded, the lot. I don't really want to be part of Gaz's checklist but he has got a charm and a girl has got needs... I'm going to make a beeline straight for him."
The pair end up hooking up and that didn't sit well with Charlotte when she heard the news. Fans later learnt that while Gary was away filming, she had been hospitalised with internal bleeding following an ectopic pregnancy.
Charlotte had to undergo urgent surgery after tearing a fallopian tube, and she revealed in an interview about her pregnancy, that Gary had been "lovely" to her when she told him.
However, she later found out about his night with Jem and decided to dash any hopes of romance between the pair.
Gary, meanwhile, admitted to sleeping with someone on the first night of filming, but stressed it was before he had found out about Charlotte's hospitalisation.
Now, he has suggested that he'd hoped he would have been the one to tell Charlotte about Jemma. He added: "Everyone already knew what I'd been doing. There were some things that I wanted to come back and tell certain people what had happened myself. I wanted to come back and say, 'Look, I want to tell you exactly what happened before it comes out.'
"Because that person already knew about it f**king weeks earlier, they'd built up their anger and it spoilt a lot of things."
Charlotte has since ruled out a reconciliation between herself and Gary. She admitted she still has a 'lot of hatred' towards him and said: "I don't see how anything can be forgiven..."
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