Sebastian Kim / GQ 1 / 3
Sebastian Kim / GQ 1 / 3

Tom Selleck isn't just a man's man -- he's the man's man. At 69 years old, the Blue Bloods actor is still as commanding a presence as he was back in the 1980s, when he made a name for himself as the star of the TV series "Magnum, P.I." He's such a force to be reckoned with, in fact, that GQ chose him to appear in its first-ever Age Issue as one of five "modern gentlemen" talking about looking and feeling great no matter how old you are.

Selleck's interview with the mag covers a wide range of topics, from his trademark 'stache to his decades-long career to his thoughts on Homer Simpson, plastic surgery, and sex. He also spoke at length about becoming a man and setting an example for the younger generation. 

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"I have a very positive idea of patriarchs," he told GQ. "And I think a man's got to grow into himself."

Selleck himself was lucky enough to have an example in the late James Garner, with whom he worked on The Rockford Files in the late 1970s. Now that he's the veteran on set, he tries to offer the same kind of guidance to his "Blue Bloods" costars, including Donnie Wahlberg, Bridget Moynahan, and Will Estes.

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"We all like each other, and we don't have anybody stir the pot on "Blue Bloods." I like to think I've set some of that example," the "Three Men and a Baby" star told GQ. "I'm older than most of the actors. I play the patriarch, and it's a rare opportunity to show a positive example...I don't believe in playing characters that aren't flawed. He's got issues, but at the same time, most dads on TV are idiots. Homer Simpson is an idiot." 

Selleck doesn't take kindly to bumbling men on television -- or in books. He even refused to read the "Berenstain Bears" series to his daughter because "the father's always an idiot!"

His own dad, Robert Selleck, who died in 2001, "was a great guy, a great example," the younger Selleck said, adding, "I get a lot like him [as I get older]."

Another thing that's changed with age is the star's relationship with his wife of 27 years, Jillie Mack. "I think love has gotten deeper. Simpler...There's just not a lot of bulls--t. We know we love each other," he explained.

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Selleck noted, too, that while the physical part of the relationship dwindles a bit -- "it's fair to say you don't have sex as often as you did when you were 30," he told GQ -- the emotional part continues to evolve. "It just grows more, kind of, satisfying...I think some of that comes with age, some of that comes with the good part of the familiarity," he said. "I don't think the infatuation stage of any relationship lasts forever, but it can grow into something."

Speaking of growing things...any advice for men trying to rock a mustache? "Go through puberty. Very important," Selleck joked. And if you still can't grow one after that, you may be out of luck. "Ashton Kutcher told me...'I can't grow one,'" the actor recalled. "Part of that's genetic. You either got it or you don't."

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Selleck definitely has it -- in spades. But if the day comes when his rugged good looks fail him, he's not opposed to getting a little help. 

"I've never done it. That's not to say I won't," the Jesse Stone star told the mag of plastic surgery. "I don't have a problem with it as long as it's not just vanity...I don't have anything really against it, if I can look at it as a tool and not a kind of narcissistic manifestation of vanity, which it probably is anyway; but I do think there's a difference between that kind of vanity and your work," he said. "If it allows you to do your job and be accepted in a larger variety of things, I think it's okay." 

Read GQ's full interview with Selleck here.