Mario Singer and Kyle "Kasey" Dexter looked "very flirty" at the Women's Health Party Under the Stars in Bridgehampton, New York, on Saturday night, an onlooker tells PEOPLE. The two were also photographed together in Sag Harbor.
Ramona, 57, first filed for divorce in January after she reportedly caught Mario cheating. Still, the couple (who are parents to 19-year-old daughter Avery) reconciled shortly after.
"All marriages hit bumps, some bigger than others," the businesswoman told PEOPLE in April. "We have a history of 25 years together and we have been very happy."
But on Thursday, Ramona Tweeted that they had split again.
"I have decided to move on with my life without Mario. I tried my best to make my marriage work. I am excited for the new chapter in my life," she wrote in her post.
Overwhelmed by all your love and support! Thank you xo— Ramona Singer (@ramonasinger) August 8, 2014
It looks like Ramona is also enjoying some beach time this weekend: The Pinot Grigio mogul Tweeted photos of her relaxing time with gal pals on a boat and hanging by the pool.
Another lunch poolside with friends .. Ever have zucchini blossoms ?? Yummy pic.twitter.com/EZMILM6Wbn— Ramona Singer (@ramonasinger) August 10, 2014