“I can’t do this scene with you. It’s disgusting”: Kaley Cuoco and Johnny Galecki Had a Full-Blown Fight in The Big Bang Theory Over 1 Scene That Made Both the Actors See Red

In the sitcom world, the chemistry between co-stars is key, but sometimes even the closest co-stars clash (and it can be over something that people usually don’t fight about). Kaley Cuoco and Johnny Galecki, the infamous Penny and Leonard on The Big Bang Theory, experienced a similar moment, and they really did see red.

Kaley Cuoco and Johnny Galecki from the series The Big Bang Theory | Warner Bros. Television

Kaley Cuoco and Johnny Galecki from the series The Big Bang Theory | Warner Bros. Television

During filming, a particularly contentious scene led to an intense argument, pushing both actors to their limits. But what was this fight about? 

Kaley Cuoco and Johnny Galecki’s Tuna Tiff: A Real-life Drama Behind the Scenes

Kaley Cuoco and Johnny Galecki from the series The Big Bang Theory | Warner Bros. Television

Kaley Cuoco and Johnny Galecki from the series The Big Bang Theory | Warner Bros. Television

Remember Penny and Leonard’s will-they-won’t-they romance in The Big Bang Theory? Well, the actors behind them, Kaley Cuoco and Johnny Galecki, had their own off-screen drama. But unlike the show’s scripted fights, this one fight involved…tuna. No, seriously. Tuna. 

Apparently, it all stemmed from Galecki’s lunch choice when he showed up late to set, and then, to make matters worse, he decided to munch on tuna during a scene that didn’t involve food. Admitting Cuoco had a full-blown fight with Galecki, the actress spilled the beans to CBS’s Watch magazine in September 2010 (via Vanity Fair):

I can’t do this scene with you. It’s disgusting! Go eat somewhere else and then come back and do it!

Galecki tried to downplay the stench. “It’s my f**king tuna, man,” he defended himself. But for Cuoco, the odor was a scene-stealer, because it smelled awfully horrendous. Things escalated quickly and the couple stormed off in a huff. Speaking about her tuna reaction in the magazine interview, Cuoco called it quits on working with Galecki during the scene, stating,

I’m not working with tuna-head today. I just can’t!

But here’s the twist—despite the fishy fight, their bond remained unshakeable. And why wouldn’t it? After almost twelve years of filming the show together, they were both practically married. However, this silly fight only deepened their bond as co-actors and a couple. 

This also goes to show that even the closest co-stars can have their off days, making them see red. But that’s okay—sometimes all it takes is a little understanding (and maybe a breath mint or nose plug) to overcome them. 

Why did Kaley Cuoco and Johnny Galecki Break Up?

Kaley Cuoco and Johnny Galecki as Penny and Leonard

Kaley Cuoco and Johnny Galecki from the series The Big Bang Theory | Warner Bros. Television

The Big Bang Theory wasn’t just about wacky neighborly antics or science experiments. In the early days of filming the show, it turns out that Kaley Cuoco had a major crush on Johnny Galecki, which later turned into a real-life love story. 

But like Sheldon’s social experiments, not all love stories have a happy ending. Galecki revealed that their future vision was different, and the show’s intensity added pressure, which is why they had to part ways. It was a mutual decision and there were no hard feelings involved, as both the actors alluded to PEOPLE. 

The Big Bang Theory, though a matchmaker, also played a part in their split. Galecki shared, “The show intertwined our lives. We barely had space for casual chats.” They realized they were better as best friends, a sentiment also echoed by Cuoco.

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