Ashton Kutcher's Twin Brother Michael Shares Why They Drifted Apart (Exclusive)

The twins brothers sit down for a vulnerable conversation in 'The Checkup With Dr. David Agus.'

Ashton Kutcher and his twin brother, Michael, are getting vulnerable like they never have before. In an exclusive sneak peek clip for the upcoming Paramount+ show, The Checkup With Dr. David Agus, the twin brothers sit down together for the first time to talk about Michael's medical struggles and the changing nature of their relationship through the years. 

When Dr. Agus asks the siblings why they drifted apart for a while, Michael candidly replies, "Jealousy for sure, at least on my part."

In the clip, Ashton talks about how his brother's health struggles made him feel guilty for his own success. 

"How do I get to be this lucky? And for my brother to be born with cerebral palsy, then have a heart transplant, then have this random blood clot. These things where you're like, 'Who has to go through that? How do I get to be this lucky?'" the actor shares.

Adam Bettcher/Getty Images for Starkey Hearing Foundation

According to the Mayo Clinic, cerebral palsy is a group of disorders that affect movement and muscle tone or posture. It's caused by damage that occurs to the immature, developing brain, most often before birth.

Ashton also recalls something Michael told him years ago that changed his outlook on the way he thinks about his brother's setbacks. 

"There was a moment in all of this where I moved to New York and was starting to get some traction with my career and Mike came out to visit and stay and he looked at me and he said, 'Every time you feel sorry for me, you make me less,'" Ashton says. "He said, 'This is the only life I've ever known, so stop feeling sorry for the only thing I have.' And that then created an entire shift back to where I think we are today, which is straight up equals. That's it." 

The Checkup With Dr. David Agus' first three episodes will premiere Tuesday, Dec. 6 on Paramount+, with the final three episodes debuting Monday, Dec. 12. 

ET spoke with Dr. Agus ahead of the show's premiere, and he talked about Ashton's emotional appearance on the show. Dr. Agus is Ashton's doctor and has been his friend for a long time.

"So just watching the interactions of Ashton with his brother rehashing what happened when his brother went into heart failure from a virus -- a viral infection caused his heart to swell up and not work and so unless he would have a transplant within days he would've died -- and Ashton rehashing those memories of, you know, the person he loved most in the world, his brother, going through this and he wasn't able to ... could you imagine, you can't you just push your brother along?" he reflects. "He had helped his brother with cerebral palsy and some social issues at school but now here's an issue that he can't fix and watching that emotion pour back was really powerful."

"Obviously emotional now bringing it up decades later with his brother by his side was powerful," he adds. "His brother lives in Colorado, has a remarkable normal life despite having these setbacks now and is able to live with those things that he went through and has an amazing family and is very successful."

RELATED CONTENT: