“Teen Mom 2” stars Leah Messer and her first ex-husband, Corey Simms, have had one of the most contentious years yet on Season 6 of the hit MTV reality show, which might make the latest rumor about them hard to believe. The former couple, who divorced after Messer cheated with her ex-boyfriend, Robbie Kidd, hooked up, In Touch Weekly wrote in an exclusive report Thursday.

The former couple was supposed to be discussing their twin daughters, Ali and Aleeah, 5. But instead of talking, they were doing something else and the gossip spread in their hometown in West Virginia, Radar Online added.

“Leah recently had sex with Corey in the back of his work truck,” an insider told In Touch Weekly. “She was just supposed to meet with him to talk about their daughters, not have sex!”

teen mom 2 cast leah messer jenelle evans kailyn lowry chelsea houska The cast of "Teen Mom 2" Season 6. From left: Chelsea Houska, Jenelle Evans, Kailyn Lowry and Leah Messer. Photo: MTV/Viacom

Messer, 23, recently divorced her second husband, Jeremy Calvert, but the apparent fling means Simms, 26, cheated on Miranda Simms, his wife of two years. “He’s admitted the affair to Miranda,” the insider told Radar Online. “It’s a huge mess, and all their friends know about it.” If the rumor is true, it could be devastating to Miranda Simms, who is reportedly pregnant with his third child.

He and Messer have engaged in a bitter battle for custody over their twins. After the “Teen Mom 2” star sought therapy for “stress and anxiety,” Simms accused her of abusing presciption pain pills. Neither Simms nor Messer has responded to the claims. In fact, the last time Simms tweeted was nearly two weeks ago, when he indirectly addressed rumors about his ex-wife.

To see the latest drama unfold, don’t miss “Teen Mom 2” on Thursdays on MTV at 10 p.m. EDT.

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