Gay actor T.R. KNIGHT was left bemused by a recent tabloid report that he enjoyed a double-date with Katherine Heigl and her fiance Josh Kelley - because his supposed boyfriend was Heigl's mother. Knight, who 'came out' as a homosexual last year (06), following a row between Isaiah Washington and Patrick Dempsey on the set of his TV show Grey's Anatomy, insists he's single. He says, "Recently Kate and her fiance Josh Kelley and me and her mom went out to dinner, and it was reported that it was with me and my new boyfriend. "But that was her mom. So I guess I'm dating Katherine's mom right now."