Last night (7June), fans watched Charlotte and Marty tash on after a few drinks, with Charlotte later breaking down in tears as she confessed all to Gary.
Immediately after locking lips with Marty, she admitted she had "f**ked up", and despite trying to reassure Gary her kiss with Marty had "meant nothing", it didn't stop him from leaving the house.
Now, Gary has opened up on how he really feels about the kiss and has hinted it is "closure" for him to start moving on from Charlotte.
Speaking to Geordie Shore's Confession Cam, Gary recalled his conversation with Charlotte and said: "Found out that Marty and Charlotte kissed when they were p*ssed last night at work. I'm actually confused about what the hell is going on. For once, I'm giving Charlotte everything she wanted. Everyone thought I was going to mess up, the girls were saying they don't trust us... and then she goes and does that."
He added: "I'm actually devastated... this is how she repays me."
Gary had made it clear to Charlotte he was only interested in her when they returned to the Geordie Shore house for its Big Birthday Battle series. Proving he was serious about their romance, Gary asked Charlotte to officially start seeing him, and he whisked her off on the couple's first official date too.
The pair had even been speaking about their future outside of the show, with Gary telling Charlotte he wants her to be his "girlfriend."
After hearing she kissed Marty, though, he appears to have had a change of heart. Gary said: "I need to know if me and Charlotte are going to work in this house, or closure so I can move on. At the minute, that to me is closure."
Charlotte, meanwhile, said she hopes she and Gary can work things out.
Sharing her regret over that kiss, Charlotte said: "I told Gary that I kissed Marty and I'm absolutely gutted about it. I think I've ruined a good thing that we had going on. For the first time in five years, he actually wanted to be with us. He was being and treating us so nice and I went and f**ked things up for us.
"I don't know whether we're ever going to come back from this and I don't think he'll actually forgive us. I haven't got a clue why I kissed Marty, I haven't got a clue... because I'm an idiot. I'll never ever do this again."
Charlotte revealed: "I was starting to fall head over heels for Gary again and I've just messed it all up. I hope that this all works itself out because if it doesn't, then that means me and Gary are over for ever."
Geordie Shore: Big Birthday Battle continues Tuesday 14 June at 10pm on MTV.
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