The pair caused a storm in 2003 when the Kids star was shown performing explicit, unsimulated fellatio on Gallo in the arthouse movie.
Sevigny later played down the controversy by suggesting she and Gallo were dating offscreen during the making of the film - but Gallo has now spoken out to insist they were never lovers.
And he has apologised to the actress after she told Playboy magazine earlier this month (Dec10) that she will "probably have to go to therapy at some point" as a result of filming the scene.
Actor/director Gallo tells New York Post gossip column PageSix, "Chloe and I were never boyfriend and girlfriend. In 1995 we made out once in Paris... I feel Chloe has suggested we were boyfriend and girlfriend to lessen the boldness of her appearance (in The Brown Bunny)... and to portray herself as a devoted girlfriend and victim rather than a great radical performer.
"Chloe brilliantly understood that the media would persist in thinking that she did it out of loyalty to me... I am sorry she feels the experience was so startling that she needs therapy to resolve her feelings."