His revelation comes just weeks before the release of a new biography about Tate's husband, Oscar-winning director Roman Polanski, The Daily Mail reported Friday. Tate, who starred in the campy "Valley of the Dolls," and four other friends was killed Aug. 9, 1969, by followers of Charles Manson.
Known for his role as Major Randolph Doryan in David Lean's epic, "Ryan's Daughter," the Tennessee-born Jones said he began his affair with Tate when she was six weeks' pregnant with Polanski's child.
When asked by the British newspaper during his interview in Los Angeles why he revealed his relationship now, Jones said, "I don't think I'm betraying any confidence by talking about it."
"I loved Sharon and she loved me," he said, adding he had "no intention" of breaking up their marriage.
"I loved being with her," he said of Tate. "Other women I've been with, I couldn't remember if my life depended on it, but she stuck in my mind."