In the clip, Lorre begins to get visibly emotional up as he slates the last take filmed in front of a studio audience. The scene on hand features Penny (Cuoco) and Leonard (Galecki) in a hotel room delivering their lines before Galecki gets choked up and apologizes.
"Let's go from the top," the director says off camera, before Lorre jokes, "I can't slate it again, Johnny."
“We're not talking about anything out of the ordinary yet!” Parsons told ET. "We're still texting about stupid day-to-day stuff, and that's another thing that will be interesting as time goes by. It’s like anything else in life when you can't imagine how it's going to be until you get there."
Parsons, 46, said the end of the CBS series will likely dawn on him in the fall, when he would have usually gone back to work.
"It hasn't really hit me yet, completely, that it's over. Mostly because the way our schedule worked for 12 years, this was an actual break that we had," he said, referring to the show’s summer filming hiatus. "I'm looking forward to September where I'd normally be working and we'd start airing. That's when I think certain things will start hitting me."
Fans can also get their hands on The Big Bang Theory: The Twelfth and Final Season on Blu-ray and DVD on Nov. 12. The release will feature a featurette on the final episode, the CBS special Unraveling the Mystery: A Big Bang Farewell, the cast's 2018 Comic-Con panel and a gag reel.
In addition, all 279 original episodes spanning over 12 seasons are in The Big Bang Theory: The Complete Series, which will be available on DVD and a premium limited edition Blu-ray. The complete set will feature nearly 12 hours of extras along with an additional disc that includes three exclusive and never-before-seen featurettes!
For more from the final days on The Big Bang Theory set, watch below.