Nicole Murphy Exposed!

Nicole Murphy had a secret romantic fling in the Caribbean with former NBA star Jim Jackson in early July -- the exact same time she says she suspected Michael Strahan of cheating on her.

 Photos of Nicole and Jim at the Dorado Beach Ritz-Carlton in Puerto Rico, where they stayed from July 7 through July 10.

You see them in a cabana on the beach ... and they got very snuggly.  People at the hotel says they were hugging, kissing ... definitely affectionate.

Sources close to the exes says.. Nicole had gone to P.R. with some girlfriends, and just happened to run into Jim -- an old friend -- and even though they "hung out" ... it was nothing serious.

Michael knew Nicole was taking the trip with her GFs, but was not aware anything went on with Jackson.

 

Nicole now says she and Michael were "on a break" when she hooked up with Jackson -- but she did not feel the relationship was over.

Still ... it's interesting ... she's accusing Michael of cheating but she was clearly playing the field.