It looks like the honeymoon is officially over. Amber Portwood and her fiancé Matt Baier will go head-to-head on Monday night’s installment of “Teen Mom OG.” In episode 9, the 25-year-old MTV reality star and her 46-year-old partner will butt heads over Amber’s behavior.

The scene begins with Amber and Matt sitting in the backseat of a minivan. When Matt question’s Amber about her solemness and asks her to “cheer up” she blames her quiet demeanor on her social anxiety issues. Matt disagrees, claiming his bride-to-be simply changes when the MTV cameras start rolling.

“You’re a different person when these cameras come on. I’m telling you. I don’t care what anybody says,” Matt says.

“It’s not the cameras. It’s people. It’s always been that way. It’s always people. It has nothing to do with the f---ing cameras dude,” Amber hastily responds.

Matt continues to disagree, stating Amber behaves differently when the “Teen Mom OG” crew is nearby. But Amber continues to fight back.

“It has nothing to do with it. I have anxiety. I don’t like being around a lot of f---ing people,” Amber says. “You already know this. I’m the same way at home. It f---ed up that you would even say that about me.”

While Matt does apologize for his initial comments, he later disses Amber once again. In response to Amber repeating his statement that she changes when the cameras are around, Matt asks her to “grow up."

“Can you do that for the cameras? Can you grow up?” Matt asks.

“Can you f--k off? That’s what you can do,” Amber responds.

Check out the sneak-peek video from “Teen Mom OG” episode 9 below:

Matt was introduced into the “Teen Mom OG” universe in episode 6. Amber told the show’s producers that she hide her romance with the Boston native, whom she met through Twitter, because she “wanted to do it right,” and avoid putting him on camera as long as possible.

While it appears Amber’s relationship with Matt is on the rocks in the forthcoming “Teen Mom OG” episode, she is rumored to be following through with her wedding plans. In March, In Touch reported that Amber was tossing around the idea of having a “TV wedding.”

“She hopes MTV will film her wedding so that they can help her foot the bill,” a source told the magazine. “It’s going to be such a special moment in her life and Amber really wants to share it with her fans.”

Episode 9 of “Teen Mom OG” premieres Monday at 10 p.m. EDT on MTV.