Not long after announcing the two were engaged, "Teen Mom 2" star Jenelle Evans is denouncing boyfriend Nathan Griffith as a cheater.

Radar Online reports Evans "ripped" her former fiancee and father of her child over the weekend on Facebook, alleging that he has been cheating with Jessica Henry.

But the website adds Griffith wasn't about to take all the criticism lying down.

"I was with Jessie before and I'm with her again," he told the website. "Jenelle and I are not together and I did not cheat on her. She knows we have been broken up."

The on-again, off-again couple have a year-old son together, Kaiser, and Griffith hinted to Radar that he may be growing more concerned about his son's welfare.

"Jenelle is crazy," he said. "But we have a family together and I believe in second chances, so I gave it to her. I have a big heart. But now I am done. I can't go back to all of that."

Griffith claims his ex has consistently threatened him, going as far as to insist she plans to ruin his life. He has previously been arrested on domestic abuse related charges.

"I just don't care anymore," he added. "I don't care. I can't take it anymore."

Griffith places the blame for many of their problems squarely on the shoulders of MTV, the network that airs the reality show they both star on.

"MTV feeds into her ego," he said. "They want her to get upset about things. When I got arrested the crew was there and they knew that I wasn't hitting her. They just don't care. That's messed up."

Griffith added that he now honestly believes his ex is addicted to drama and their relationship has become toxic. He concedes that the two did reconcile for a short period, but quickly split again and basically he has been with Henry since then.

Still, Griffith admits that he may not be completely done with the show.

"If I do another season it is going to be very different and on my terms," he said.