'Teen Mom 2' Star Leah Messer Deals With the Aftermath of Reunion Drama in Exclusive Premiere Preview

Leah Messer is in the middle of some serious drama between exes Jeremy Calvert and Corey Simms amid the fallout from last season of Teen Mom 2's reunion special. In a PopCulture.com exclusive preview of Tuesday's season premiere, Messer is trying to keep things civil between her two co-parenting partners as the feud escalates on social media, but feels stuck in the middle.

During the reunion, Calvert accused Simms of not being there for 10-year-old Aliannah's muscular dystrophy doctor appointments, to which Messer's ex-husband did not take kindly, tweeting at the time that even if he had to take unpaid days from work, he would be at the next reunion filming to defend his name. "And for Mr. Dad of the year to run his mouth about not going to doctors appointments.. how many have you been to there big guy??" he added on social media. In addition to Ali, Simms shares 10-year-old Aleeah with Messer, while Calvert is dad to the MTV star's 7-year-old daughter, Adalynn.

Rolling her eyes at her exes going back and forth, Messer calls their disagreement "so stupid," but admits to her producer that she resents having to play peacemaker. "Has Corey been to all the appointments? No. I'm not saying that he has," she explains. "However, it's what's worked for us, and I literally said that on stage. So when Jeremy said that, it just added fuel to the fire, and now I feel like I have to put it out. It puts me in the middle of something that I really don't want to be in, because I have to co-parent with both of [them]."

Simms is still fuming when Teen Mom 2 cameras check in with him as he sits down with friends Jared and Josh, who confess the statements Calvert put out there make him seem like a "deadbeat dad" who doesn't care about his daughter's diagnosis. "I was upset at what was said, but also the fact that I didn't have the opportunity to explain or defend myself," Simms says of having to miss filming for work. "But it just overtook my emotions whenever I watched it." Furthermore, Simms explains he was confused why Calvert would say that, as he has a good relationship with both Messer and his fellow co-parent. "Where did it come from?" he asks. "I thought we were doing good."

Speaking with PopCulture ahead of the premiere, Messer said all her girls are "happy and healthy," although it's becoming difficult for Ali to see her sisters reach milestones she isn't able to physically. Messer said she always encourages Ali to try her best with things like buttoning her pants, and oftentimes the little girl's willpower leads her to triumph in the end. "I've never seen a child so determined," Messer said. Don't miss the season premiere of Teen Mom 2, returning Tuesday, Sept. 1 at 8 p.m. ET on MTV. For more on your favorite Teen Mom stars from PopCulture, click here.