Couple developments in the rumored Paulina Gretzky, Dustin Johnson split ...
1) A deeply connected source tells us they're NOT broken up.
2) The alleged mistress is adamant she NEVER hooked up with the PGA superstar.
Here's what we know ... Paulina ignited the breakup rumors after wiping all traces of Dustin from her Instagram page (don't worry, her bikini pics are all still there).
Reports surfaced shortly after that a woman named Yassie Safai was "at the center" of the split -- the insinuation was that Dustin had an affair with her behind Paulina's back.