'RHONY' Ramona Singer's Ex Mario Dating Mistress Kasey Dexter: Shows Off GF at NYC Party

Their secret rendezvous might have been the talk of the Upper East Side last year when news broke that Real Housewives of New York City star Mario Singer was stepping out on his wife Ramona with mistress Kasey Dexter, but it looks like the most recent news might shake the socialite's circle even more. Turns out that now that Ramona has moved on from her cheating husband, it might have pushed Mario into the hands of Dexter, and it is even being speculated that these two might have taken their scandalous fling and turn it into an official courtship.

According to Radar Online, patrons of a swanky New York City party were stunned when they saw Singer attending the event with Dexter on his arm. However, it might be what a source close to Dexter is saying that could be the most questionable comment of all.

According to a source, the former Florida fitness instructor is telling people that her and Mario are actually in love.

"She says they're in love," an insider explained to the news site, adding that their romance is "definitely back on."

But first lemme take a selfie selfie selfie selfie #famday #lastdayofsb14 pic.twitter.com/PrFliCv2VP

— Avery Singer (@averysinger) March 15, 2014

It seems that Dexter had no qualms flaunting her man at the party even though some of Ramona's co-stars, both past and present, were in attendance. Sonja Morgan and Jill Zarin were just a few of the people at the 25A cover bash on Sept. 28, watching on as Dexter and Singer flaunted their relationship.

According to the NY Daily News, an eyewitness stated, "Mario introduced her as his girlfriend, and said loudly to whoever would listen, 'My life is better now, it just keeps getting better and better.'

However, despite the onlooker saying that Mario was proudly boasting about his new girlfriend, another source says that Singer was a more apprehensive, as Radar states, he didn't want to be photographed with Dexter.

"Mario was reluctant, but Kasey wanted to get her photo taken with him," an insider explained to the site.

We previously reported that Ramona has been linked to a new man, so we aren't sure she isn't letting her ex's new romance get to her too much.