Alex Kompothecras is currently expecting his first child, a baby girl, with girlfriend Alyssa Salerno

And the plot thickens.

In PEOPLE’s exclusive sneak peek at Tuesday’s episode of Siesta Key, Alex Kompothecras comes clean to his girlfriend Alyssa Salerno — the future mother of child — about where things really stand with his ex Juliette Porter.

“So I have something that is not a huge deal,” he begins. “But I feel like you should hear it from me before you hear it from someone else. A few weeks ago, I was talking to Juliette. It started off small, and then one night I ended up staying on phone with her for a really long period of time — like, six hours.”

“I just felt bad, like, her whole perspective on this breakup —” he continues, but Alyssa cuts him off.

Alyssa Salerno
| Credit: MTV/ Youtube
Siesta Key Juliette Porter, Alex Kompothecras
Juliette Porter and Alex Kompothecras
| Credit: Juliette Porter/Instagram; MTV

“Wait, wait, wait,” she says, eyebrows raised. “Why am I just know hearing about all of this?”

As it turns out, it’s because Juliette is on her way to the very party the couple is currently at.

“Because she’s coming,” Alex says. “I would rather you hear it from me than from her. The last thing I need is for her to run up to you and give her side of the story before I tell you.”

“So it takes her coming here for you tell me this?” Alyssa demands. “Does that not sound really f—ing sketchy? That you’re like, ‘Oh s—, I need go up to Alyssa and tell her this.’ That’s kind of bulls—.”

RELATED VIDEO: Robby Hayes and Juliette Porter Reveal There Was Tension with the Siesta Key Cast from ‘the Get-Go’

Alex insists he’s “not lying,” and simply “didn’t think it was a big deal.”

“How is it not a big deal?” Alyssa fires back. “Your ex calling you and you’re talking for six hours?”

“I just want you to know,” she warns. “I’m not a dumba–.”

After Alex, 24, announced in December that he and Alyssa are expecting their first child, a baby girl, Juliette, 22, came out swinging and claimed she hooked up with the dad-to-be while he was with Alyssa.

“Weird how he cheated on her with me several months ago but ok,” she wrote in a since-deleted comment on The Morning Toast’s Instagram post about the announcement. Alex has not publicly addressed the allegation.

Siesta Key airs Tuesdays (8 p.m. ET) on MTV. The show is currently no. 1 in the time period with P18-34 and W18-34 (Nielsen; LSD data ranked on 000s, 1/7/20-2/11/20.)