Cuoco, 30, and Galecki, 40, who star as Penny and Leonard on the hit CBS show, split in 2010 after secretly dating for two years. Rumors that the two got back together came to light after Cuoco announced she was divorcing her husband
, Ryan Sweeting, in September. Cuoco slammed the romance rumors for the first time
back in October, captioning an Instagram pic
, "So sorry to disappoint, but no home wreckers or secret flings going on here. Me and @sanctionedjohnnygalecki are just the best of buds -- Leonard and Penny will just have to suffice!"