Despite dating, Kaley Cuoco denied having sex with Johnny Galecki on the set of The Big Bang Theory.

The Big Bang Theory completely changed the sitcom genre when it premiered in 2007. Fans got a closer look at the lives of four nerdy but incredible scientists and their attractive neighbor, Penny. While there were other equally entertaining plots, the relationship between Penny (Kaley Cuoco) and Leonard (Johnny Galecki) was one of the most beloved.

While the characters got their happy ending on the show, the cast on the other side dated for a couple of years before splitting (2008-2010). But the book "The Big Bang Theory: The Definitive Inside Story," released for the show's 15th anniversary in 2022, detailed some lesser-known moments between Cuoco and Galecki.

While Kaley Cuoco and Johnny Galecki broke up almost 14 years ago, they still maintain a close friendship with each other. It was because of this connection alone that they revealed several intimate details about their relationship in the book "The Big Bang Theory: The Definitive Inside Story" (via Vanity Fair). The actress recalled the moment show creator Chuck Lorre snapped the duo hiding behind a car in the parking lot.