The Cosmopolis actor was speaking at a press day for The Twilight Saga: Breaking Dawn - Part 2 on July 16, nine days before Stewart publicly confirmed reports of a fling with her married Snow White and the Huntsman director Rupert Sanders.
Pattinson is quoted as telling journalists: "No, I've never been betrayed by people who are actually in my life, like my friends or even my acquaintances. No one has ever done anything."
According to The Mirror, the 26-year-old went on to claim that celebrities are "the most conservative people in the world" due to the prevalence of gossip sites.
"Being a successful actor... if you just had the good side of fame it would have been unbelievable," he said.
"Now actors are the most conservative people in the world because you can't do anything. Literally... you can't do anything at all. You can't trust anyone because it all becomes part of your career."
Copyright: WENNPattinson also said in a magazine interview in April that he does not understand why people cheat.
The actor was said to be "in good spirits" on Friday (August 3) during his first public sighting since news of Stewart's fling broke.