Dr. Rey -- I Thought Knife Guy Was JOKING

4/19/2011 9:45 AM PDT

Dr. Rey -- I Thought Knife Guy Was JOKING

Dr. Rey says he didn't freak out when a man pulled a knife on him at a Hollywood club this weekend -- because at the time, he thought the dude was just joking around ... and never intended to stab him.

TMZ met up with the unsliced reality star in L.A. yesterday -- where he explained, "If I had perceived this for real, then I would have fought him off ... but I thought it was a joke."

Rey says after the camera shut off Friday night -- the knife-wielder approached him again and asked to take a picture together ... and Rey obliged.

As for legal action -- Rey tells us he probably won't press charges because, "I'm not 100% convinced it wasn't a prank."

TMZ broke the story -- some d-bag with a blade pulled out his weapon right in front of Rey outside of Roxbury nightclub over a disagreement about Rey's wardrobe ... but the d-bag's friend ripped the guy away from Rey before the situation escalated.