Amber and Matt's trip to Sin City was meant to celebrate her recent completion of parole, but the duo's vacation hit an unfortunate rough patch during tonight's "Teen Mom OG" episode: The Bostonian punched a wall in their hotel room. The cause of his surprising burst of aggression? Too many alcoholic beverages.

"He doesn't drink, and I've never really seen him drink -- so when he got drunk, he gets angry," the 25-year-old admits in the "Teen Mom OG: Featured Moment" clip below, adding that she saw a side of her fiancé she "didn't like."

Since viewers didn't witness the incident firsthand -- Amber and Matt opened up about it to A's longtime producer Heather -- how was M behaving before the outburst?

"He becomes that drunk that's like, 'You don't love me anymore,'" the Indiana native reflects, while imitating her beau's intoxicated speech. "Like that's all I was freaking hearing for like five hours. And I was like, 'What the f**k are you talking about right now?'"

Has Matt had any repeats since the couple's return to Indiana? And what was Amber thinking during the entire ordeal? Watch the video to hear her candidly open up, and be sure to catch the season finale of "TMOG" next Monday at 10/9c.