Kaley Cuoco and Johnny Galecki are very amicable exes today, but y co-stars were put in a very awkward position while they were filming their hit sitcom. Cuoco and Galecki secretly dated while filming the CBS comedy and privately split up early into the show's 12-season run. «We dated really early on for almost two years. It was very early on in the show,» Cuoco recalled on Dax Shepard's podcast.