Big Bang Theory's Kaley Cuoco, Johnny Galecki were 'crying' during Sheldon-Amy proposal scene

The Big Bang Theory season 10 ended with Sheldon traveling to Princeton to propose to his girlfriend Amy, and the other TBBT actors couldn't help but cry at that emotional scene.

During a panel at Comic-Con, the cast and crew gathered to speak about the 11th season of the CBS show and talked about how everyone gathered to intently watch the perennial moment between Sheldon and Amy.

Johnny Galecki, who plays Leonard Hofstadter, said he "came as close to crying as is possible for me".

"We were all crying," Kunal Nayyar, who plays Rajesh, said, while Kevin Sussman, who plays Stuart, also echoed similar sentiments: "I came as close to crying as I'm capable of."

Penny actor Kaley Cuoco revealed that she keeps a Polaroid camera around to take candid pictures of the cast and when she arrived to capture the moment, "basically everyone and everyone's mother and friend was behind the camera for this one scene, even though we all knew what was going to happen".

Cuoco admitted to tearing up, and explained, "(There's been) so many years and so many relationships have transformed, and to see that be this pinnacle of the season, it was just really cool. We've all come a long way."

The cast and producers also reminisced about their favourite guest stars on the show. Showrunner Steve Molaro recalled the episode in which the late Adam West guest starred.

"He had a line in the script where he told Leonard and Koothrappali, 'Don't ring my doorbell or my poodles will go crazy,'" Molaro said.

West also asked if his character could have a tougher dog, "like a Rottweiler". When Molaro explained that a poodle was funnier, West said, "Well, I have poodles in real life, so I guess it's fine."

Executive producer Steve Holland recalled James Earl Jones and Carrie Fisher being on set together for an episode, which also marks the first time that the Star Wars stars had ever met. "She came out and she said 'Dad!' and then they hugged," Holland said.

The Big Bang Theory will return for season 11 on Monday, 25 September at 8pm ET on CBS Network.