'Married At First Sight' stars Gab Bartlett and Sean Donnelly are hooking up

Married At First Sight stars Gabrielle Bartlett and Sean Donnelly are reportedly "sleeping together."

According to Gab's ex 'husband' Nasser Sultan, the pair were seen at one of Ryan Gallagher's recent comedy gigs in South Australia.

"Gab is sleeping with Sean from Adelaide," Nasser said on KIIS FM's Kyle and Jackie O Show on Monday morning. "Apparently she flew down to see Ryan's gig and [Sean's ex 'wife'] Jo [McPharlin] caught them in the hotel room. The story will come out today I guarantee it."

Nasser said the pair were close during filming of the show last year.

"I tell you, she always had a soft spot for Sean because he used to come into our room to have drinks," Nasser added. "It's one of those things like 'Come on Sean, go home, it's two in the morning. But him and her used to stay up quite a while."

According to NW magazine, Gab and Sean haven't stopped talking since the show ended.

"Ryan's show was at the Arkaba Hotel so some of the guys had rooms upstairs," an insider told the publication. "Gab flew over especially to spend time with Sean… and one thing just led to another."

When Jo saw them leaving the same hotel room together, she was reportedly quick to "put two and two together."

"Jo couldn't believe her eyes," the insider added. "She gives them her blessing but it was a bit of a surprise."

Both Gab and Nasser and Sean and Jo ended their TV marriages before the show's final commitment ceremony.