Catie is desperate for a loophole when it comes to not having to be monogamous with Josh.

In this exclusive clip from Sunday’s new episode of “90 Day Fiancé,” the couple has a heart-to-heart the night before their wedding. Catie — who’s had an issue all season with constantly trying to make out with her friends and blaming it on having obsessive compulsive disorder (OCD) — shockingly asks Josh if threesomes would be OK once they’re married.

The question comes after Josh looks for reassurance from her that she’s committing to being with just him once they tie the knot.

“Monogamy is what I’m making a commitment to, and, like, just committing to you and only you and kind of looking for the same in return,” he tells her.

She responds, “Can we never make out with anyone again?”

Josh awkwardly stays silent as she continues, “But what if in the future we, like, want to have a three-way or something, like, both of us? Does that fit into monogamy?”

Not surprising given his head-scratching behavior this entire season, Josh gives in despite very clearly not wanting an open relationship.

“If we were both wanting that and talked about it, that would fit the definition,” he responds. “I don’t know if that is what I want, but I don’t know what the future holds.”

Catie admits to cameras that she has “mixed feelings” about if she can stay faithful to Josh.

“I don’t have any doubts about him,” she insists. “It’s more like I have doubts about how I’ll act in that situation.”

She adds, “Like, I just love flirting. I’ve always loved flirting.”

In a previous episode, Catie’s mom told cameras that her daughter has always been selfish growing up.

“I don’t want to blame a lot of her behavior on OCD, but she’s got a lot of internal struggles with all those voices telling her things that she doesn’t want to be hearing all the time,” she noted.

“I mean, she’s burned some relationships — a lot of relationships, several friendships — just because, she’s a lot, and people get tired of it.”

“90 Day Fiancé” airs Sundays at 8 p.m. ET/PT on TLC.