Marie Osmond celebrated her 60th birthday in style on the set of The Talk on Monday (Oct. 14), where she recently signed on as a co-host. The singer invited her older brothers on the show to give their last-ever performance as the Osmond Brothers, but the fun didn't end there. Marie's other brother, Donny, joined in the party, surprising his sister by showing up in person.

Alan, Wayne, Merrill and Jay Osmond formed the original Osmond Brothers lineup, a barbershop quartet that attracted national attention when they made regular appearances on the Andy Williams Show from 1962-1969. They reunited one day after Marie's actual birthday on Sunday (Oct. 13) to sing a poignant song titled "The Last Chapter," performing in front of a screen depicting highlights from Marie's life and career while she visibly wiped away tears.

After that emotional farewell performance, the Osmonds were all cutting Marie's cake with her co-hosts on The Talk when they announced that Donny had provided a special birthday message. They cut to a video of Donny performing a production number complete with background dancers, singing a funky, horn-driven song in tribute to his younger sister. "Add another candle / Another year, it's true / But 60 years / Sure looks good on you," he sings in the humorous clip.

The music continued after the video ended, and Donny Osmond himself walked out of the wings onto the set from behind, where Marie didn't see him until the audience began to react. She looks genuinely surprised in the clip above as she goes to give him a hug, while he tells the audience that it required stealth planning to keep his surprise under wraps.

"Did you really think I would miss this reunion?" Donny demanded comically.

"There are no secrets in Hollywood, and especially no secrets in the Osmond family," he says. "I lied to everyone" to make sure his appearance was actually a surprise, he adds.

Osmond turned serious in sharing his favorite memory of his sister, recalling that when his older brothers were already performing and he and Marie were too young to join them, she was "my buddy. We would always play together ... we got in so much trouble. I've always called her my partner in crime, and she really is. She's my partner."

Donny would join his brothers in the '70s, shifting their group into a prominent pop-rock act before teaming with Marie for a TV variety show titled the Donny & Marie Show, which ran from 1976-1979 on ABC. Most recently they teamed again for a long-running Las Vegas residency called Donny & Marie that wrapped in November.

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