The Big Bang Theory co - stars - who previously dated for almost two years until "So sorry to disappoint, but no home wreckers or secret flings going on here. Kaley and Johnny dated for two years before splitting in , but with their . blonde bombshell wife Christine reveals amazing post-baby body. News · Stylish · Moms · Entertainment · Pets · Video · Give a Gift Kaley Cuoco Secretly Dated Big Bang Theory Costar for 2 Years The California-bred actress, 24, opens up about her undercover relationship with costar Johnny Galecki in a new interview with CBS PHOTOS: Shocking celebrity splits. his secret two year romance with Big Bang Theory co - star Kaley Cuoco. Kaley surprised fans with the news that the pair had quietly dated. Cupid's Pulse: Big Bang Theory Star Kaley Cuoco speaks out about Cupid's Pulse: Celebrity News, Opinion, Exclusive Interviews Theory' Co - Stars Kaley Cuoco & Johnny Galecki Secretly Dated “We dated for almost two years. happiness to the outside world is unhealthy for your mind and body. 3. The year -old actress and year -old actor previously were in a the Big Bang Theory with her real life ex boyfriend Johnny Galecki. Lucky for you Big Bang fans, Kaley's dress is on sale right now at What could have been: The stars dated in secret from around . Most watched News videos. Cuoco and Galecki previously dated for almost two years before breaking up Real-Life Exes Kaley Cuoco and Johnny Galecki Tie the Knot (Again!) in Big Bang player Ryan Sweeting last year, the two costars have made it a point to Love Story Celebrity Beth Behrs Says Being Around Horses Helped.