How A Tuna Snack Led To A Fight Between The Big Bang Theory's Johnny Galecki And Kaley Cuoco

Many avid TV watchers recognize Johnny Galecki and Kaley Cuoco best for their role as the central duo in CBS's beloved sitcom "The Big Bang Theory." With Galecki as the pop-culture-loving, ultra-geek Leonard and Cuoco as his theater enthusiast neighbor Penny, watching the two fall in love is one of the sweetest aspects of the series. However, things haven't always been as smooth for Galecki and Cuoco as their on-screen dynamic might make it seem.

As dedicated fans may be aware, Galecki and Cuoco dated for a time during the early years of "The Big Bang Theory" (via People). Though the pair eventually split up, they remained close friends and co-workers. Of course, their on-screen characters' romance only continued to blossom, to the point that Galecki and Cuoco were convinced the writers of "The Big Bang Theory" were messing with them by adding more intimate scenes between them post-breakup. However, one of the duo's most unexpected off-screen conflicts had little to do with their past relationship and everything to do with tuna.

Glamour senior editor Jessica Radloff's new "The Big Bang Theory" book is stuffed with interesting anecdotes from the legendary sitcom. It also happens to chronicle the tuna-centric conflict that Johnny Galecki and Kaley Cuoco found themselves embroiled in while filming one day.

"We got into a fight because he was eating tuna during the scene and I got pissed," Cuoco recalled. "It was a day Johnny was late, so I was already annoyed. And he decides during the scene, which did not contain food, that he was going to rehearse and eat tuna."

According to Galecki, his seafood snack was part of a diet to lose weight for a play. Though he had checked with Jim Parsons about the smell, who said it didn't bother him, Cuoco couldn't stand it.

"It smelled so horrendous, and finally I was like, "I can't do this scene with you. This is disgusting. Go eat somewhere else and then come back and do it," Cuoco said. "So Johnny walked off and threw his tuna in the trash. He was like, 'Fine!' We both stormed off. I was like, 'I'm not working with tuna-head today. I just can't.'"

While the tuna incident proved to be an unexpected spat between the pair, it was a minor blip in an otherwise strong friendship. "Johnny and I are very close," Cuoco told E! News in 2021. "We talk multiple times a week."