Jim Parsons, who played Sheldon Cooper in The Big Bang Theory, revealed that he had a great on-screen chemistry with co-star Kaley Cuoco, who played Penny. Shooting scenes together was always easy and fun for the pair. Their kiss scene was also shockingly easy to shoot in front of a live audience, and they got it right the first time. However, Parsons' experience was drastically different when kissing Mayim Bialik, who played Amy. He was sick with a bad respiratory cold during the scene, while Bialik worked hard to remain healthy by gargling peroxide between takes.