Drew Rosenhaus' Wife -- Bikini Party with Dan Bilzerian ... Before Blowout Fight

Drew Rosenhaus' wife was partying with epically-bearded Hollywood playboy Dan Bilzerian in the weeks before her blowout fight with the sports mega-agent ... and even posed for some close-up ass shots ... TMZ Sports has learned.

We broke the story ... Drew and Lisa Thomson got into a heated verbal altercation at their Miami home Sunday night -- with the police responding to the scene to cool things down.

But the question -- did the pics trigger the war at home?? Our sources are divided ...

One source connected to the couple says Drew was pissed about the photos (taken roughly 1 month ago) -- and went off on his wife for putting her ass on display like a Spring Break party chick.

But another source close to Lisa is adamant Drew "didn't care" about the pics or why she was on the boat with Dan in the first place.

One thing's for sure ... the marriage seems to be over -- and judging by the pics, Lisa probably won't have a hard time finding a rebound.