Watch the full interview with Donny and Marie Osmond Monday. "Piers Morgan Tonight" airs weeknights on CNN/US at 9 p.m. ET and on CNN International at 0200 GMT (live simulcast), 1200 GMT, and 2000 GMT and HKT.
CNN -- Donny Osmond was the Justin Bieber of his day. And while the show biz veteran has not yet met his 2011 pop star counterpart, he has some advice for him.
"Put the seat belt on, buddy, because it's going to be a bumpy ride."
Donny and Marie Osmond are guests on Monday's "Piers Morgan Tonight." The brother-sister duo joined the CNN host from the stage of the Flamingo Hotel in Las Vegas where they perform.
"That kind of success at that age can really bite you in the shorts as it were -- the proverbial shorts so to speak," continued Donny. "I look at the experiences that I've gone through as a teeny bopper. You know ... I look at Justin Bieber ... and my heart breaks for him, because I know what he's going to go through. He knows. Everybody knows."
Donny went on to say that Bieber is "going to go through so much heartache, 'Baby, baby, baby. Oh my' he's going to hate that. He probably hates it right now just as much as I hated 'Puppy Love.'"
Both Donny and Marie agreed that many young entertainers today "just jump into the business," that they "get a lot of fame and fortune," and "feel entitled."
"They forget about getting out there and working and doing all those little gigs -- 366 days a year and going through the work, going through the motions," said Donny.
The pair said that their strong work ethic was instilled in them by their father, who Donny said taught them "if there's something worth doing, it's worth doing well."
Marie told Morgan she feels "blessed" to have grown up working with Sammy Davis Jr., Dean Martin and Elvis Presley.
"They didn't look at it as being a celebrity," Marie said. "They looked at it as being an entertainer. It was their job."
Donny said that the "mark that a lot of people miss nowadays" is that "they leave out the heart and soul. And that's what I learned from Sammy Davis Jr., from Frank Sinatra, is when you went to ... those shows, you got to know them."
Donny recalled seeing Presley's closing show at the Hilton in the 1970s, the night before he and Marie were set to open on that same stage.
"I remember watching the 'King' onstage. He could do no wrong. I mean the -- the attitude was in the palm of his hand."
Presley came to visit him in his dressing room the following evening, Donny said, and politely said "'Hi, everybody. I'm Elvis Presley. I just wanted to come say hi and good luck.'"
"The king of rock and roll just walked through the door, and he's a real person," said Donny. "It taught me a lot about leaving the star onstage. When you go onstage, you're just another person."
Donny said that an entertainer's genuine love for the audience is missing from many of today's acts. He said he and Marie go to great lengths to make sure their audiences "walk away feeling that they got to know us better."
Donny said Davis once told him, "The day you stop caring about your show is the day you should quit."
Marie also spoke about her recent remarriage to her first husband, Steve. The couple married 29 years ago but divorced after three years. She wore her original wedding dress, and the couple's 28-year-old son -- who went through his entire life with separated parents -- served as a witness.
Marie said that when she broke the news of the engagement to her son, he hadn't been aware his parents were even dating.
"I was recording an album. It's out. It's my first inspirational album. ... There's a song on there called, 'Tell Me to Breathe.' ... I went to my son and I said, 'I'm going to marry your father again and I need a song that says my love to him.' And so he helped write that song. And that's my song to my husband, Steve."
The couple married in Las Vegas, and Marie chose the birthday shared by her mother, Olive Osmond, who died in 2004, and her son Michael, who committed suicide last year.
"That way they could all be there kind of symbolically," said Marie. "As a matter of, we took a picture with -- I took a picture with Steve and all the kids. And I had Donny stand in for Michael. Then we're going to take -- put Michael's face on his body."
Marie said she will never get over the loss Michael, who was 18 when he died.
"There's always a place that is set in your heart at the dinner table," said Marie. "There's always a celebration when he's there."
She said the proceeds from her inspirational album will go to the Children's Miracle Network on Michael's behalf.
Donny, who has been married for 33 years, told Morgan that his marriage was "the only thing that kept me sane."
"Point to another teeny bopper star who didn't go through the drugs, the alcohol, the women," continued Donny. "My wife is the one that got me through it."
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