Affleck, 49, spilled about his wall art while appearing on The Kelly Clarkson Show Wednesday. The actor told host Kelly Clarkson that he picked out the poster, which was released with Prince's 1981 album Controversy, when he was nine years old.
"My favorite musician was Prince, who is a genius," he told Clarkson, 39, who praised her guest as a "very sophisticated nine-year-old."
When an image of the poster popped up on the screen behind them, Clarkson exclaimed, "Oh my God, this is the poster!"
Affleck confirmed, "That is it," before adding, "Listen, I was nine years old, I was a big Prince fan."
The Controversy poster features Prince, who died in 2016, pictured in only his underwear. The musician poses in a shower while wearing a pair of black underwear and putting his arms behind his head.
Rodin Eckenroth/FilmMagic; Richard E. Aaron/Redferns
When Clarkson asked what his mom's response to the poster was, Affleck insisted, "My mom was very understanding. I took the poster, put it up, thinking like, 'Yeah, that's the guy. That's the artist I like.'"
Alamy Stock Photo
Affleck said when his mom first saw the poster, she was puzzled by his decor choice.
"I watched like 15 different thoughts go through her head," he explained," and she was like, 'That's lovely.' "
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Affleck stopped by Clarkson's daytime talk show with his Tender Bar costars Tye Sheridan and Daniel Ranieri. The trio discussed their new film, which is based on J.R. Moehringer's 2005 memoir.
Affleck talked to PEOPLE about working on The Tender Bar with director George Clooney, who he said helped him create a schedule where he could spend more time with his kids. Affleck shares daughters Violet, 16, and Seraphina, 12, and son Sam, 9, with ex-wife Jennifer Garner.
"My life has really changed a lot. Once I had kids, it became very obvious to me that the priority was time with them," he said.
He added, "George was spectacular in that way. He's a dad too and would let me out on the weekends or cut me early. He really understood and appreciated how important it was for me to see my kids."
The Tender Bar is now streaming on Amazon Prime Video and playing in select theaters.