In the latest episode of Married At First Sight Australia, Dean owned up to his infidelity to the best friends of his wife, Tracey.
His mistress, Davina, exited the programme in the previous episode, but their affair continues to impact his relationship.
Tracey became angry at Dean before the pair met her friends, when he downplayed his cheating with statements like "whatever", "I've apologised" and "I didn't cheat".
While he remained unsure of why she was cross, he got a similar reaction from her best buddies.
"I met up with this girl for a drink," he told them.
"That girl expressed a pretty intense interest in leaving her husband and being with me. I did also express some interest in being with her. We talked about leaving our partners and getting together."
The ladies looked shocked.
"That's horrible," one of them stated.
"I don't really think cheating on your spouse is acceptable. It just shows a lack of commitment and a lack of respect. That doesn't really sit well with me."
The full Married At First Sight Australia episode can be viewed on ThreeNow.