After more than a year fighting over custody of their twin daughters, Ali and Aleeah, it's not a secret that Teen Mom 2 star Leah Messer and her first ex-husband, Corey Simms, are NOT friends.
But in MTV's just-released preview clip from next week's Teen Mom 2 finale special part 2, the former spouses completely lash out, and make shocking accusations about each other.
First, the two discuss Simms' current wife, Miranda Patterson, who acted openly hostile to her husband's ex over the series' 6th season.
"She's got issues with Miranda because she's jealous of Miranda," Simms tells moderator Dr. Drew Pinsky of Messer, 23. "Me and Miranda have a normal, functioning life. She can't keep a husband for more than two years!"
Messer, who as RadarOnline.com exclusively reported, finalized her divorce from ex-husband #2 Jeremy Calvert in June, then stabs Simms, 25, with thinly-veiled cheating accusations.
"Never in my life would I be jealous of Miranda. Where were you at during your first couple months of marriage?" she asks.
In past reunions, Messer has claimed Simms begged her to get back together just a week before his 2013 wedding to Patterson. She also said Simms was unfaithful to his new wife during the early days of their relationship.
In an even more shocking rumor, reports claim Messer and Simms had sex in recent months.
After more bickering, Simms then seems to refer to Messer's widely publicized drug problem. (The mother of three claims she went to rehab for anxiety and depression over the summer, while sources tell Radar she sought treatment for a prescription pill addiction.)
"If I had f***ing done what she done, I wouldn't see my kids!" he shouts. "If I would have done…"
"Monkey!" Messer shouts, which Pinsky explains is her "safe" word.
"There's stuff she doesn't want to go into," the host explains to Simms and the audience.
To catch the drama, watch the video above and don't miss the reunion's second half, airing Wednesday at 9 pm est on MTV.