Actress Kaley Cuoco found filming sex scenes with former boyfriend, actor Johnny Galecki, a tricky affair.

During an appearance on the podcast "Armchair Expert", Cuoco shared that she began dating Galecki at the start of the hit sitcom "The Big Bang Theory", and broke up two years later, reports people.com.

"We dated really early on for almost two years. When we did the pilot, I was crushing so hard on Galecki but he had a girlfriend," she said, adding that they eventually started dating.

Cuoco starred as Penny in "The Big Bang Theory", who ends up getting married to Galecki's character Leonard.

"We got together and just fell mad for each other for two years, but then we broke up. Luckily Johnny and I came out of it so brilliantly and we're closer today than we ever were," she shared.

Talking about their sex scenes in the show, Cuoco said: "When we broke up obviously it was a little sensitive for a minute, but I remember those weeks that (show creator) Chuck (Lorre) had written these episodes where all of a sudden our characters were like sleeping together every other second. Johnny and I talk about it and I think Chuck did that on purpose," she said, adding that the scene "came out of nowhere".

Cuoco and Galecki starred in "The Big Bang Theory" from season one in 2007 until the last season got wrapped up last year.

The actress is now married to Karl Cook, while Galecki has been dating Alaina Meyer since 2018 and have welcomed a son with her last year.