The Big Bang Theory might have followed a nerd who fell in love with the girl next door, but in real life co-stars Kaley Cuoco and Johnny Galecki were falling in love for real. Kaley Cuoco’s romance with costar was very hit among fans.
Kaley Cuoco once embarked on a whirlwind romance with one of her closest co-stars on set of The Big Bang Theory.
Kaley played girl next door Penny in the CBS sitcom, while Johnny Galecki played Leonard, the nerd who falls in love with her. But behind the scenes, the two actors were falling for each other for real.
The pair first met back in 2007, on the set of the comedy show – and Kaley admits she had a huge crush on him from the get-go, while they were both in relationships with other people. Kaley admitted in the book The Big Bang Theory: The Definitive, Inside Story of the Epic Hit Series: “I had a very big crush on Johnny early on. Kaley Cuoco’s romance with costar was very hit among fans.
“I was so not even hiding it. He has such swagger. We were both dating people at the time, but I only had eyes for Johnny. Then, when I found out he had eyes for me too, I was like, ‘Uh‑oh, this is going to be trouble’.”
Things came to a head during their first ever on-screen kiss, with Kaley’s character Penny dressed up as a sexy cat for Halloween. She explained: “I knew I looked real cute in that outfit, so I was feeling really good about myself. And I knew he thought I looked cute because he commented on how cute I looked in that outfit earlier. But I was definitely nervous before that kiss.
“I was like, ‘Get me out of here,’ because he had to hold me up and we had to do this really close thing. Even my cheeks were red,” she added.
Secret romance
By 2008, the pair started dating for real – but wanted to keep it on the down-low from fans. It all kicked off in season one episode The Nerdvana Annihilation, when Leonard imagines rescuing Penny from the elevator shaft in their building.
Kaley admitted: “I think we fell a little in love in that elevator shaft.” While Johnny himself gushed: “We felt something, yeah. I think that was a massive turning point [in our relationship].
“At that point, both she and I knew that something mutual was felt, and that it was going to be more of a distraction from the work to try and continue to ignore it than to actually recognize it and surrender to it.” After that, Kaley split from her boyfriend at the time. Kaley Cuoco’s romance with costar was very hit among fans.
There was a good reason for their romance to remain a secret, however, as Kaley explained: “He was very protective of what the fans would think, because we wanted them to want Leonard and Penny together so badly, that if they saw us together in real life, it could ruin the fantasy.”
Tragic Split
In 2009, the couple quietly called things quits because they both “wanted different things”. Johnny explained: “We just had very different interests in what I think we wanted from our experience of life.”
That wasn’t the only reason. Kaley admitted they simply ran out of things to discuss. She said: “Johnny and I also ran out of things to talk about, because we’d be at work all day, and then we’d go back to one of our places together, and say, ‘So how was your day? Simon was funny today, right?’ And we’d laugh because we had no mystery. Kaley Cuoco’s romance with costar was very hit among fans.
“But we were together for a long time. We really adored each other, and we were lucky because as our break-up was happening, there was no foul play, there was nothing bad about our relationship… it just ended.” However, there was “some hurt” for a while before things got back to normal.
It took until 2010 for the pair to admit they’d ever been together, with Kaley confessing to CBS Watch! Magazine: “Everyone was always asking, and we deny-deny-denied. And I’m like, ‘Why am I denying this person that I love?’”
The pair “couldn’t do anything” together without risking it getting into the public eye, but became “dear friends” instead. Johnny told Vanity Fair: “I think I might value my relationship with her more than any other previous relationship or relationship afterwards… We just have such a bond that I appreciate so much. And I think that’s part of our great friendship.”
Sex scene tension
After their split, Kaley says the number of sex scenes between their characters only increased exponentially – and accused show creator Chuck Lorre of adding them to “mess” with the former couple. She told hosts of the Armchair Expert podcast: “When we broke up obviously it was a little sensitive for a minute, but I remember those weeks that 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 just to f*** with us. Because that came out of nowhere. All of a sudden these characters were all up on each other.”
However, creator Lorre denied the claims, claiming: “No. Not at all. Making a good show has no room for f***ing with anybody. There’s no, ‘Let’s mess with Kaley and Johnny’. The goal was to make a great show and make every minute of every episode count. And that was the only goal.
“We don’t have that kind of freedom to risk a TV series that you put your heart and soul into to mess with somebody’s head. No. I think that’s charming that they think we had the mental capacity to mess with them.”
Moving on
After their split, Johnny was there for Kaley at her wedding to her now ex-husband Ryan Sweeting. She married the former tennis player after meeting him on a blind date, but after 21 months of wedded bliss, filed for divorce, citing irreconcilable differences.
She later started dating NETFLIX star Tom Pelphrey, welcoming daughter Matilda in March 2023 – but the pair are in “no hurry” to tie the knot. They also share rescue dog Opal.
Johnny, meanwhile, began dating girlfriend Alaina Meyer in 2018, and the pair welcomed a son, Avery, a year later. However, by 2020 the pair had separated.
His romance with Kaley wasn’t the first time Johnny dated a co-star. As a teen starring in Roseanne, he fell for Sara Gilbert – who he would later star alongside in The Big Bang Theory. But during their relationship, Sara realised she was a lesbian – but remains close pals with her ex-boyfriend.
