Since The Big Bang Theory was on the air for 12 seasons, the main cast members worked with a huge number of guest stars. Actors have mixed thoughts about their time on the overwhelmingly popular sitcom. Some celebrities like Charlie Sheen didn't like appearing on TBBT. Other actors sounded excited about the opportunity.

While it's fun to hear what guest stars thought about The Big Bang Theory, it's also cool to hear the main cast's perspective. Jim Parsons and Mayim Bialik, who played the sweet and smart couple Sheldon Cooper and Amy Farrah Fowler, explained during a Comic-Con interview that there was one guest actor who made a scene pretty difficult to film.

Here's what happened...

What Did Jim Parsons And Mayim Bialik Say About A Guest Star On The Big Bang Theory?

Whether fans love attending Comic-Con in person or are happy to watch YouTube footage of certain panels afterward, there's no question that this fun event can lead to a lot of juicy reveals. Often, when the cast of a popular TV series sits on a panel and answers questions, they end up sharing some hilarious or memorable experiences that people wouldn't hear about otherwise.

When The Big Bang Theory cast spoke at a Comic-Con panel in July 2011, Jim Parsons talked about a filming experience that sounded tricky.

The actors were asked about a scene or memory that they liked the most from season 5, which would air in September 2011.

Jim Parsons said, "My favorite moment of the season was also with Mayim, but it's not something that made it, well, it is on film but you wouldn't know what was going on... We had to do a scene, do you remember this..."

Parsons stumbled over his words a little and he and Bialik laughed while he tried to explain the experience. As he got further into it, it was clear that a guest star made it tough for him and his co-star to act out a certain scene.

Parsons said, "Mayim and I were attending an event-type thing and the person... the person that we were watching do this event, he kept staring at us and he was saying all of his lines directly to us... It was really hard to do, like he would stare at us while were acting."

Bialik added, "He was supposed to be making a speech speaking to a group of people, but whenever they were filming just me and Jim, he wasn't pretending like he was speaking to everyone. He was looking directly at us."

Bialik and Parsons decided that they would stare in the same direction so they would know what to focus on.

The actor joked, "Thank you for helping me with that story. That was horrible. You saved that whole thing."

Jim Parsons and Mayim Bialik definitely played characters on The Big Bang Theory who are more than a little awkward. However, it sounds like this scene was on another level, and it was tough to get through. While they could laugh about what happened, it's clear that this scene could have gone much smoother. It must have been frustrating for them.

The actors are super talented, though, and they figured out how to save the scene.

The Big Bang Theory fans likely watched this scene and had no idea what was really going on. This is a great example of the magic of Hollywood and how fans are often totally in the dark about what can happen on a TV or movie set.

Did Jim Parsons And Mayim Bialik Share The Identity Of The Big Bang Theory Guest Actor?

As soon as Jim Parsons began talking about filming an awkward The Big Bang Theory scene, Mayim Bialik knew exactly what he was talking about.

However, the actors didn't share who they were referring to.

Of course, they might want to keep the actor's identity a secret since they said that it was such a challenging scene. It makes sense that they would want to spare the actor's feelings and not say something harsh about them publicly.

Since Bialik and Parsons didn't explain who they were talking about, it's hard to know which guest star it was. It's also tough to know exactly what scene they mentioned during the Comic-Con panel.

While the actors didn't go into any more details and the conversation moved on naturally, it was still interesting to hear Parsons share this memory. This experience proves that Bialik and Parsons had a great professional relationship.

It sounds like they were able to listen to each other and meet any challenges that came up. Staying flexible is definitely a good skill to have as an actor, especially when someone stars in a sitcom.

The actors have always said that they loved their time on set together. In 2021, Mayim Bialik talked about Jim Parsons in an interview with Us Weekly and shared more about acting alongside him.

She explained, "Jim and I had a lot of nice moments together on set and I think one of the things that worked so well for us as actor partners, and maybe as producing partners too, is that we're not overly sentimental as humans, which I think is helpful.

It was helpful in our acting and also in the way we kind of processed ending a decade together."

Mayim Bialik often mentioned some fun behind-the-scenes tidbits when interviewed. She talked about the episodes of the popular sitcom that she liked the most with TBS.com and mentioned the season 7 episode "The Locomotive Manipulation."

She said the episode included "Amy and Sheldon's first kiss on the train" and continued, "I love how our writers let this intimacy unfold. It's awkward and sweet and tender. And fun fact: Jim had a full blown flu when we filmed this. I rinsed my mouth out with peroxide between takes and did not get his flu!"