'90 Day Fiancé': Isabel's Unsure If She'll Choose Gabe If Her Dad Can't Accept He's Trans (Exclusive)

Isabel isn't sure she can walk away from her dad even though Gabe has already moved to Colombia to be with her.

Isabel and Gabe are at a serious crossroads. In this exclusive clip from Sunday's new episode of 90 Day Fiancé: The Other Way, Gabe worries that his fiancée, Isabel's, father won't accept him once they tell him he's transgender and Isabel admits she doesn't know if she can walk away from her father if he objects to the relationship.

Isabel says her father is "very religious" and "totally not open-minded." Meanwhile, Gabe tells cameras he didn't know Isabel's father was as conservative as he is.

"But I didn't know the gravity of the situation, that there was literally like a list of reasons why he wouldn't accept me," he says. "The only negative comments that I get online are either from trolls or religious people saying I'm a sinner, I'm going to burn in hell, that I have to repent before God strikes me down. It's pretty terrifying because it might influence how he perceives me after he finds out that I'm trans."

When Gabe and Isabel's friends bluntly ask Isabel what she'll do if her father says he won't talk to her anymore if she continues to see Gabe -- who has already moved to Colombia from Florida to be with her -- she admits she's not sure.

But Gabe interjects, "But whether he says yes or no, I want you with me because I live here because of you."

Of course, it's not that simple for Isabel.

"I'm also here for you, but my family and parents are also very important to me," she notes.

Isabel, who has two children from a previous relationship, explains to cameras that she's scared of her parents' reaction since in the past, they've been right about her relationships.

"And I don't want to think that they'd be right again," she says. "It's what scares me the most."

90 Day Fiancé: The Other Way airs Sunday at 8/7c on TLC.

ET recently spoke to Gabe, who explained why he didn't tell Isabel he was transgender at first and defended paying her bills. Watch the video below for more.