'Big Bang Theory' stars Johnny Galecki, Kaley Cuoco reveal offscreen love story

The actors of the two star-crossed lovers, Leonard and Penny, from the Big Bang Theory have recently revealed their offscreen love story on the set through an interview for a book about the show.

Johnny Galecki, who portrayed Leonard Hofstader, exclusively dated his co-star, Kaley Cuoco, for two years, from 2008 to 2010. Even though the relationship ended, they have shown to the public that their friendship prevails. It is no surprise that the duo have such an unbreakable bond since they worked for over 12 years together on the popular American sitcom.

Both actors were interviewed by journalist Jessica Radloff for her soon-to-be-released book entitled, The Big Bang Theory: The Definitive, Inside Story of the Epic Hit Series. A couple of excerpts from a chapter of the book were recently published in Vanity Fair.

Kaley admitted that her real-life relationship with Johnny had a great impact as to why their characters worked so well together. She commented that they actually have a similar relationship as Leonard and Penny, "always giving each other shit" yet still having each other's backs. "It made our relationship funny and endearing," she added.

Though the two were currently dating other people during the early stages of filming, Kaley confessed that she had developed a massive crush on Johnny early on. Johnny responded that he is usually oblivious when people flirt with him and that, "I had zero idea of any sort of crush before Kaley and I began dating."

In one of the scenes of the first season, their characters were scripted to kiss in an elevator shaft. Johnny commented that Kaley looked really happy in his arms, even though it was a hard stunt to pull. Kaley further added, "I think we fell a little in love in that elevator shaft."

They both continued to detail the process of their courtship, which involved Johnny inviting Kaley to a cast get-together at the San Ysidro Ranch and both of them breaking up with their respective partners. Eventually, Johnny asked Kaley out on a date, and the rest is history.