Jim Parsons and Mayim Bialik may have signed on for cameos on Young Sheldon, but Kaley Cuoco, Johnny Galecki and other OG cast members turned it down flat – causing a major divide between the once close costars that looks to be unfixable.

“It’s crazy how things have reversed in the six years since Big Bang Theory went off the air,” an insider exclusively reveals to Closer. “Jim has become a key architect of the interconnected universe via his executive producing and narration role on Young Sheldon, which made him tens of millions of dollars beyond the vast fortune he built on the original show, where he made more than $25 million per year in the final seasons.”

The source continues, “During the same time period, Mayim had the profound epiphany that being a dedicated TV comedy actress, not a part-time game show host, was her destiny. And she, of course, sees a similar future to what Jim has enjoyed during the last few years as Warner Bros. seeks to make more shows set in this continuity. But today, in 2024, Kaley and Johnny aren’t involved whatsoever.”

Johnny, 49, and Kaley, 38, seem to be fine leaving the show in their rearview, according to the source. Kaley’s especially seen success with streaming shows like The Flight Attendant and Based on a True Story.

“They’ve both moved on in their own ways,” the source adds, “with Kaley pursuing a diversified slate of comedy and drama projects while also guiding and boosting the career of her partner Tom Pelphrey, and Johnny focused mostly on producing but also loving his downtime as a dad of young kids while only occasionally doing acting jobs.”

BBT’s Jim Parsons and Mayim Bialik Annoyed With Costars
Steve Granitz / Getty Images

However, money isn’t the issue when it comes to the big divide between Kaley, Johnny, Jim, 51, and Mayim, 48.

“Yes, they all have more money than you can possibly imagine but if you had predicted eight years ago that this would be the dynamic among the cast in the 2020’s, you would have sounded insane,” the source explains. “Knowing Jim and Mayim, it has to be annoying to them that they appear publicly to be squeezing every dollar out of this franchise while Johnny and Kaley follow their respective muses, but it’s not that simple. [Jim and Mayim] are true believers in the power and international reach of the Big Bang Theory universe, and Johnny and Kaley just feel like they have better things to do with their time.”