Teen Mom
Leah Messer with her childrenInstagram/Leah Messer

The reunion special of "Teen Mom 2" is going to be an explosive one, as a new report claims that Jeremy Calvert plans to expose his wife's alleged cheating ways on the show.

An insider told Radar Online that although Calvert has been involved with other girls, it was all after he split from Leah Messer. However, the father of two-year-old daughter Adalynn believes that his ex-wife has been with a number of guys during the three years they were together.

"Yes, Jeremy hooked up with other girls, but that was after he split from Leah," the family insider said. "Leah didn't just hook up with one guy, there were tons!" the source said, adding that her former husband has proof to support his claims.

"She won't be able to deny the truth in front of everyone. She won't get away with her lies for long," the source explained.

A strain in their relationship came to light last October when Calvert accused Messer of cheating on him, and even called her a "slut" on microblogging site Twitter.

"Well that was a surprise kinda u did it to Corey and now me with the same person good job slut," Calvert, a pipeline engineer, wrote, referring to Messer cheating on ex-husband Corey Simms with her former boyfriend, Robbie Kidd.

"Yeah I don't give a fuck done protecting ur a** good luck," Calvert continued. "Caught ya b*tch."

He then called out Kidd, writing: "Go back to Mingo and have a wonderful f*cking weekend with Mr Kidd."

Although Messer -- who is currently in rehab for pill addiction, stress and depression -- denied cheating on Calvert, Kidd eventually confirmed the news.

Messer and Calvert's divorce was finalised on 8 June while the 23-year-old was still in rehab.

"Leah participated on the phone from rehab," an insider told In Touch. Because the duo had an uncontested divorce, the entire procedure, including their daughter's custody, was over within 15 minutes, the insider said.

The next season of the MTV's "Teen Mom" series premieres on 8 July.