The former Bethenny Ever After and The Real Housewives of New York City star was sporting a black and white string bikini, showing off her fit figure, while Cerussi was wearing a white bathing suit. The pair were photographed in the water together.
"Bethenny is dating," a source close to Frankel told Us.
An insider also told the website that Frankel stayed with Cerussi -- who reportedly works in New York in financial services -- at the Delano Hotel in Miami Tuesday for New Year's Eve.
"They've been all over each other since they got here," said the insider.
"Bethenny was with [Michael] and looked very happy on New Year's Eve," a source told People. "They kissed at midnight and other times during the evening. They looked like they were having a great night."
Frankel seemed to accidentally reveal she was dating a new guy in October when she slipped some information to a guest during her talk show. This is apparently the first guy Frankel has dated since her failed relationship with estranged husband Jason Hoppy.
"It's very unfamiliar to me not to want to meet anybody, to not feel a need to fill that void. And I've accepted the fact that I might never find that great love and that authentic real relationship the way that it's supposed to feel," Frankel, who has a three-year-old daughter named Bryn with Hoppy, told People at the time.
"Men aren't a priority right now -- at all. It would take away from important things that I'm not willing to sacrifice. With my talk show and my daughter, there's little room for anything else."
Frankel, who also previously competed on The Apprentice: Martha Stewart and is managing her ever-growing Skinnygirl empire, had also told the magazine she planned not to rush into another relationship because it's tough to open up to a man.
"A lot of me is shut down right now. I'm a little fragile," she explained. "Intimacy wouldn't be so bad, but it's hard to bridge the gap. I'm a quality over quantity kind of person. And since I'm emotionally unavailable. It may be a chilly winter."
DISCUSS AND COMMENT ON THIS STORY Reality TV World now offers Facebook Comments on our stories. To post a comment, log into Facebook and then 'Add' your comment. To report spam or abuse, click the 'X' in the upper right corner of the comment box. Get more Reality TV World! Follow us on Twitter, like us on Facebook or add our RSS feed.