Amber Portwood recently debuted her new boyfriend on Instagram and according to a new report, her former fiance, Matt Baier, isn't happy about the relationship.

While Baier recently claimed that he was in full support of the Teen Mom OG star and her new relationship, an insider has since spoken out, claiming that Baier is actually "seething" over the new man in Portwood's life.

According to a Radar Online report on August 21, when Baier was initially supportive of Portwood's romance, he didn't realize that the new man in her life was Andrew Glennon, a producer he worked with during his time on WEtv's Marriage Boot Camp: Reality Stars Family Edition.

“Matt knew she had a new guy, but didn’t know it was Andrew,” the source explained. “Now he is furious and suspects her of cheating on him.”

Meanwhile, the source added, “Amber thinks Matt is just jealous.”

Days ago, Baier spoke to Radar Online after learning that his ex was dating someone new.

“The most important thing is Amber is happy and safe,” Baier said at the time. “Amber and I were inseparable for over 3 years and we built a life together. When you love somebody that much, all you want is for that person to be happy. I support all good decisions Amber makes.”

Baier went on to reveal that he was sad about the end of his own relationship with the reality star.

“It’s over forever so there is going to be a degree of sadness,” he said. “But Amber and I are very close still, we have always been the best of friends. So she knows I am always here if she needs me and has my support.”

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