Cathy and Josh are one of the most loved-up couples on Married At First Sight. But when another bride gets flirty with Josh at the second dinner party this week, Cathy can't help but feel jealous.
Will this cause the first crack in their relationship?
Cathy, 26, tells TV WEEK she wasn't surprised that other women in the experiment found Josh attractive.
"I thought, 'Oh God, I get it. I've got the hottest guy here at the table and every bride here wants to sit next to him and get close,'" she says.
But she admits she got upset at the dinner party when she saw Josh speaking to one particular woman who he'd previously said he didn't like.
"She was really close with him, kind of all over him," Cathy remembers. "I was getting jealous. I thought, 'Well, why are you sitting there talking to her and laughing with her and letting her touch you? I'm not okay with that.'"
For the Sydney logistics investigator, trust is a huge issue in a relationship. She's been hurt before by infidelity, and she says she'd told Josh that.
"He knows about my past, he knows that my ex-partners had cheated on me," Cathy says.
Cathy hit it off with Josh from the moment they met.
"From the first five minutes being with Josh, I was like, 'Ooh, I like him. He's gorgeous, funny. I feel like he's my friend,'" she says.
WATCH BELOW: NTL's two minute speed date with Cathy from MAFS 2020
They were one of the first couples to sleep together, and went into intimacy week full of confidence.
"We were both laughing about the fact that we're going to be fine and everyone else is going to be having a hard time," Cathy remembers. "Like, 'Oh, look at us go! We're number one!'"
WATCH BELOW: Married At First Sight's Josh's Two Minute Speed Date. Post continues after video...
She says she already had "very strong feelings" for Josh.
"I would say it's that feeling above infatuation, but are you sure you want to commit to saying, 'I love you'? I was careful, but also excited because I was feeling such strong feelings," she says.
With their relationship looking so solid, could one little dinner party flirtation really shake it to its core?