"I think Fernanda's a little too young for her to be able to handle the situation in a mature way," says Jonathan in PEOPLE's exclusive sneak peek

By Natalie Stone
November 16, 2018 09:00 AM

Is Jonathan and Fernanda’s relationship on the rocks?

On last week’s episode of 90 Day Fiancé, Fernanda, 19, found Jonathan, 32, dancing with another woman in the club — just 65 days before their wedding. And in PEOPLE’s exclusive sneak peek at Sunday’s episode, Jonathan attempts to explain himself to an angered Fernanda after she storms outside.

“Do you want to get married with me?” Fernanda, who is from Mexico, asks Jonathan while sitting in their car.

“Of course I do,” the Lumberton, North Carolina, native tells her.

“Well show me, because I don’t feel that!” she says.

When Jonathan attempts to reassure her, she pushes him away and says “don’t touch me.” From Fernanda’s perspective, seeing Jonathan — whom she met at a club in Mexico and got engaged to after three months of dating — dancing with another woman is “the worst thing I can see in my life.”

“You were dancing with her,” she tells an allegedly “drunk” Jonathan, who argues: “She’s not even my type.”

In an attempt to defend himself, Jonathan explains that while Fernanda was in the bathroom, the woman came up to him and tried to dance: “I said, ‘No, I have a fiancée, she’ll be here in a second.’ ”

Fernanda is still upset and alleges that Jonathan “doesn’t respect” her, leading him to question if he can commit to marriage.

“I’m insulted by the fact that Fernanda feels like I don’t respect her. I know it didn’t look good, if you’re coming out of the bathroom and you see that situation happening, but I clearly didn’t do anything. But Fernanda doesn’t care. I think Fernanda’s a little too young for her to be able to handle the situation in a mature way,” he shares. “This is basically what my friends have been trying to warn me about. It’s very frustrating — very, very frustrating.”

“Every night we go out can’t end in a huge fight,” he says. “And, to be honest, this has to get better in order for me to go through with this marriage.”

90 Day Fiancé airs Sundays (8 p.m. ET) on TLC.