Tyrese was linked to Houston after the stars met at a pre-Grammy party in Los Angeles earlier this year.
The National Enquirer claims Houston, 47, has been "quietly dating" Gibson ever since - but the relationship is news to the hunky star.
He writes on Twitter, "Negative blogs, press, blurbs, people spreading negative things. Rumors. I rest WELL at night cause none of these things matter anymore...
"Man if ya'll don't [bleep] w this dumb [bleep].. Hahahahahaahahaa... #NEVER... I repeat.. NEVER..!!"
But Gibson's harsh denial has irked Houston's daughter, Bobbi Kristina.
Responding to the actor's tweet, she writes, "Lmao at Tyrese.. Damn it's like tht (that)?! Hah, well to clear it up, TRUST ME, MY MOM WOULD NEVER. Hah #shesroyalty."
