Simon Guobadia and Falynn Guobadia’s messy split is getting even messier.

On Thursday, Simon — who is currently engaged to Falynn’s Real Housewives of Atlanta costar Porsha Williams — threw jabs at his estranged wife on Instagram, claiming that she cheated on him and is currently pregnant with another man’s child.

His allegations came after Falynn posted a video tease of a tell-all interview she’s doing about the end of their relationship and Simon’s current romance with Williams.

“The Face of Cheating Wife…” Simon, 57, said, posting the chat’s trailer.

He then went on to claim that Falynn was unfaithful in their marriage, having an affair with an Atlanta entrepreneur, whom he identified by his Instagram handle. The two are having a child together, Simon alleged, and living in a home on Simon’s dime.

“Let’s start with why I filed for divorce,” Simon wrote. “Let’s start with who she cheated with and currently pregnant for and living in a home I paid for — post divorce. … This is how your generosity gets twisted. Let’s get started there.”

Both Falynn and her alleged partner did not immediately respond to PEOPLE’s request for comment.

Falynn does appear to have been asked about the rumors that she cheated on Simon in her upcoming interview, which was conducted by YouTuber Adam Newell.

In the minute-long sneak peek shared on social media, the 31-year-old model alleged to Newell, “Simon doesn’t get caught unless Simon wants to be caught.” (Simon previously denied that he cheated, and offered $50,000 to anyone who could prove otherwise).

Asked if she “resents” being friends with Williams, Falynn told Newell, “I meant what I said when I took my vows.”

“It hurts, it hurts like hell,” she says in the next clip, wiping back tears.

Simon and Falynn wed in June 2019. They announced their split April 22 on their respective social media pages.

“After two years of marriage and 5 years of friendship, Simon and I have made the difficult decision to go our separate ways,” Falynn wrote on her Instagram Story at the time.

“We are deeply thankful for the impact we have made in each other’s lives, as well as the bonds formed with each other’s children. This mutual decision was not made lightly,” she continued. “And despite our current willingness to be transparent, we only ask our friends and supporters to be respectful of our privacy as our family gets through this very difficult period.”

Less than a month later, Simon announced that he and Williams, 39, were engaged after a month of dating. He and Falynn have yet to finalize their divorce, though they reached a settlement in April, according to court documents obtained by PEOPLE.

Since the news broke, Falynn has only publicly addressed her estranged husband’s new relationship in a statement.

“I want to thank everyone for reaching out to me and offering their love and support,” she said, in a statement obtained by PEOPLE. “At this time, I am focusing on finalizing my divorce and healing. Sending positivity to all of you.”

This will be the second marriage for Williams. She shares 2-year-old daughter Pilar Jhena with ex-fiancé Dennis McKinley.

“We are crazy in love,” Williams said of Simon, when confirming their relationship on Instagram. “I know it’s fast but we are living life each day to its fullest. I choose happiness every morning and every night. Tuning out all negative energy and only focused on positive wishes. He makes me so happy and to me, that is what matters most.”

In her post, Williams addressed the “optics” of the situation, writing, “Simon filed for divorce from a previous marriage in January. I had nothing to do with their divorce filing. That’s between the two of them.”

“Falynn and I are not friends, and Simon’s divorce has been settled,” she added. “Our relationship is a positive, loving step forward in everybody’s lives.”