This week's Married At First Sight dinner party was one for the books. With two new couples, a bride who flirted with two other grooms, and the residual tension between Martha and Cyrell from their earlier fight, it was always going to be a tense dining experience.

The icing on top was Melissa learning that her husband, Dino, had recorded her talking privately with her sister in the middle of the night.

Ahead of the dinner party, Dino told Mel he'd heard her say "unkind things" about his wedding vows and the state of their relationship -- things Mel claims she had already said to his face prior to that phone call.

"Until this point I had not spoken to my friends or family, so Dino had gone to bed and it was the first time I had time to speak to my sister," Mel tells 9Honey Celebrity. "Halfway through the conversation I went into the bedroom to get my charger and he obviously jumped back on the bed and pretended he was asleep."

Dino and Melissa. (Nine)

She says the next day, when the cameras were back in the apartment, he decided to confront her about it so that it would be on TV.

"That was fine and I got over it, but three days later we were having a fine, fun conversation talking about our outfits for the dinner party and suddenly he was saying things to provoke me like, 'If I walked past you on the street, I wouldn't look twice at you,' and, 'After what I heard you saying to your sister, there's no way I could be attracted to you.'"

The girls rally to support Mel as the experts predict this could be the end for Mel and Dino.

That was when Mel noticed Dino's iPhone was recording their conversation.

"Then he had to admit that he had also recorded the conversation with my sister. I never knew that there was ever a recording of me and my sister until I caught him three days later trying to record another conversation," she says.

The couple's argument over the phone recording erupts at the Dinner Party.

"I think in Dino's head he had the intention of getting the recording played back at the commitment ceremony," she adds.

At the dinner party that night, things escalated and Melissa broke down in tears, with the experts expressing "grave concerns" for the couple and their future together.

Married At First Sight Season 6 airs Sunday at 7pm and Monday to Wednesday at 7:30pm on Nine. Catch up on exclusive interviews and gossip at 9Honey Celebrity. Missed an episode? Get your Married At First Sight recaps here. MAFS obsessed? Tune into 9Honey's weekly chat show, Talking Married, where you'll get the inside scoop on every episode. For more on MAFS, including past episodes and behind-the-scenes clips, head to the official site.