Rosie O'Donnell's Ex Michelle Rounds -- Looks Like Someone Is Trying to Make Rosie Jealous (VIDEO)

So on the same day Michelle Rounds filed for sole custody of the child she shares with ex Rosie O'Donnell, she hit the town with a smoking hot model. What are the odds????

Rounds was out Tuesday night at Madera Kitchen where she walked out with her arm around Carmen Ortega ... who once dated Reggie Bush and was also possibly maybe the reason Jason Derulo and Jordin Sparks split.

We can't say Rounds and Ortega are together. In fact, a rep for Ortega says they're just working on a clothing line together -- but Rounds still went out of her way to snuggle close to Ortega for the cameras to see.

Not that we can blame her.