Jason Derulo's Ex Jena Frumes Wears Red Bikini During Family Beach Day

Jason Derulo's ex Jena Frumes brought the heat to South Beach this weekend ... flaunting her beach body in a hot red bikini while hanging with her baby daddy and their son.

The fam was photographed at the W South Beach -- a five-star hotel in Miami Beach this weekend ... heading out to the sand where they had their own VIP cabana and sunbeds.

Check out the pics ... Jena stripped off her cover-up dress shortly after arriving at the beach -- revealing her steamy swimwear underneath.

Derulo's near by in his t-shirt and board short ... laughing big while watching their son -- also named Jason -- dig around in the sand.

Miami seems like a location of convenience for the family to congregate ... 'cause JD had a couple shows down in "The Magic City" this past weekend.

Jason played LIV Nightclub Saturday -- a favorite of celebs hanging in South Florida -- and then the home of the Miami Heat, the Kaseya Center Sunday.

If you don't know ... Jenna and Jason split up in September 2021, about four months after their son was born.

Jena claims that Jason's cheating ultimately ended their relationship ... though it still seems they're on good terms -- given their time out and Jason buying her a $3.6 million home in 2022.

Holidays are for coming together ... and these two are clearly crushing the co-parenting game!