Back Together? Leah Messer's Boyfriend Catches Her Texting Ex-Husband Jeremy Calvert!

Former spouses Leah Messer and Jeremy Calvert both adamantly deny rumors they're getting back together— but where there's smoke, there's fire!

The exes, who finalized their divorce last June, are not only closely co-parenting their nearly 3-year-old daughter, Addie, and her 6-year-old twins, Ali and Aleeah, with ex-husband #1 Corey Simms, they're texting nonstop, RadarOnline.com can exclusively reveal.

The only problem? Messer's boyfriend, T.R. Dues, is not happy with the very chummy rapport, sources say.

Last month, "T.R. looked in Leah's phone, and saw she had written 'I love you' to Jeremy, and even called him 'babe,'" said a source close to the 32-year-old personal trainer, who lives in Messer's Charleston, West Virginia, home. "He was furious!"

The single father of two feels so betrayed, he's even contemplating moving out, another insider claims.

"He wants to get his own apartment, just in case things go south," the insider alleged. "Friends are warning him that Leah cheated on her exes, and is likely to do it to him, too."

The 23-year-old reality star and her pipeline engineer ex-husband, 26, split bitterly amid rampant cheating rumors on both sides. But in recent months, the two have been spotted around their hometown together on family outings with Addie, signaling the end of their feud.