Married at First Sight UK's Kristina Goodsell was left 'heartbroken' by husband Kieran Chapman who moved on from their marriage with another woman shortly after they left the E4 show.
The revelation of Kieran's girlfriend caused an explosive row during filming of the reunion episode as the cast expressed their shock over the Geordie's new romance.
But the biggest reaction came from Kieran, 28, himself who broke down in tears over the realisation he had hurt ex-wife Kristina more than he ever intended.
After investing her heart and soul in the dating experiment, Kristina, 31, couldn't hide her pain, sobbing as she was forced to confront the issue head on.
Kieran was accused of being dishonest after he told Kristina their relationship wouldn't work over his commitment fears – before he started seeing someone new.
A TV source told MailOnline: 'The cast were stunned after discovering Kieran had moved on so soon after filming for him and Kristina finished.
'Kieran had expressed how difficult committing to a new relationship was going to for him after he was betrayed by an ex-girlfriend but he met someone new shortly after his marriage ended.
'He was very emotional seeing Kristina handle the fact he was seeing a new woman given he still cares about her feelings.
Married at First Sight UK's Kristina Goodsell was left 'heartbroken' after husband Kieran Chapman moved on from their marriage with another woman shortly after they left the show
The revelation of Kieran's girlfriend caused an explosive row during filming of the reunion episode as the cast expressed their shock over the Geordie's new romance
After investing her heart and soul in the dating experiment, Kristina couldn't hide her pain, sobbing as she was forced to confront the issue head on
'With Kieran's hysterical tears and Kristina doing her best to remain strong, the reunion episode was incredibly tough for the former couple to film.'
An insider added: 'Kieran's romance following his marriage to Kristina ended before the reunion episode was filmed.'
Kieran's new romance came after he and Kristina opted to leave the Channel 4 dating experiment after failing to make their marriage work.
The Geordie mechanic had expressed difficulties over coping with Kristina's Premenstrual Dysphoric Disorder, which is a mood disorder that causes severe emotional, cognitive, and physical symptoms in the run-up to menstruation.
He also said a hurtful betrayal in a past relationship, where his ex-girlfriend slept with his best friend, caused him to struggle with commitment and Kristina even reminded him of his former partner.
Kieran also spent weeks avoiding any physical or sexual contact with Kristina, saying it was because he had a cold sore but during an honest admission with the experts, said he was using it as an excuse to stay away.
Cracks in the couple's relationship deepened after they did the show's homestay separately instead of showing each other where they both live in the real world.
During their final scenes, Kieran said: 'We did our homestay separate and that was because I didn't want to take Kristina back to mine knowing where my head is at. I ask myself the question can I see myself and Kristina being together in 10 years' time…'
MailOnline has contacted a Channel 4 representative for comment.
Kieran's new romance came after he and Kristina opted to leave the Channel 4 dating experiment after failing to make their marriage work
The Geordie mechanic had expressed difficulties over coping with Kristina's Premenstrual Dysphoric Disorder
Cracks in the couple's relationship deepened after they did the show's homestay separately instead of showing each other where they both live in the real world
The couple's emotional ending saw them thank each other for the effort they made during the process, vowing to stay close friends
He continued: 'I don't know how much I have left in me for the amount of emotional support Kristina needs, that's a big deal to me.'
Speaking to his wife, Kieran said: 'I'm really sorry to put you in this position, Kristina, it was never my intention, I will always think the world of you. I just know that I cannot give you the best version of me.'
Kristina added: 'I can't just turn my feelings off overnight, Kieran knows that. I have been so patient and so understanding and so respectful, the ball has been in his court for ages… so I'm going to leave.'
The couple's emotional ending saw them thank each other for the effort they made during the process, vowing to stay close friends.
Following their last time on the sofa in front of the experts, Kristina remained confused, questioning: 'How can I go from being your perfect match, the girl of your dreams, everything, to then nothing?'