After more than 20 years as a Hollywood power couple, Susan Sarandon and Tim Robbins have called it quits. The actors met -- and began dating -- while filming the 1988 movie Bull Durham. Sarandon and Robbins, who had two sons together -- Jack Henry, 20, and Miles Guthrie, 17 -- were known for both their outspoken political and social stances and never tying the knot. "Actress Susan Sarandon and her partner of 23 years, actor Tim Robbins have announced that they separated over the summer," her rep told PEOPLE. "No further comments will be made."