Willie Nelson is opening up about his extraordinary bond with his wife, Annie D’Angelo, in the latest issue of People.

Nelson, 90, who has been married to D’Angelo, 66, for 31 years, recently described his wife as “my lover, my nurse, my bodyguard” in an exclusive interview with People set to be released in the mag’s latest issue on Friday.

“I call her my pet rattler,” says the trailblazing country star.

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“As they say, laughter’s the best medicine,” Nelson says of the secret to a long-lasting marriage. “I’ve always enjoyed a good joke.”

“We’ve got a couple of great kids,” Nelson continues. “I am proud of them and all they’re doing on their own. It’s great to have your kids with you at any time, but if they’re on the stage singing with you and they’re good, that makes it even better.”

Nelson was joined by his two sons Lukas, 34, and Micah, 33 for his 90th birthday in April, which he celebrated with a star-studded two-day concert at the Hollywood Bowl in Los Angeles, California.

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Nelson is also a father to Lana, 69, Susie, 66, Paula, 53, and Amy, 49, from past relationships, as well as his late children Renee and Billy.

Rather than preach advice to his kids, the timeless musician prefers to teach them through his work ethic.

“It’s better to show them rather than tell them,” he adds. “If they see your work ethic every day, then they realize, ‘Hey, maybe he knows what he’s doing.'”