Gwen Stefani's Sons Led Blake Shelton To Discover His Dad Instincts 

Blake Shelton and Gwen Stefani are madly in love — but the country superstar is also head over heels for her three sons.

“For a long time, it was awkward trying to figure out what my place is and in their mind too,” newly crowned Sexiest Man Alive Shelton tells PEOPLE exclusively about the rocker’s three sons Kingston, 11, Zuma, 9, and Apollo, 3 (with ex Gavin Rossdale). “The best part for me, selfishly, is discovering a part of myself that I guess I never really knew was in there. It’s definitely an instinct that kind of kicks in.”

There’s no shortage of energy with the three boys running around at home, and “there’s days where you go, ‘Oh my God, when does school start?\'” he jokes.

Watch PEOPLE Cover Story: Sexiest Man Alive — Blake Shelton, available now, on PeopleTV. Go to PeopleTV.com, or download the PeopleTV app on your favorite mobile or connected TV device.

For more of Shelton’s revealing interview—including his life with Stefani—pick up the latest issue of PEOPLE, on newsstands Friday.

“An hour later you’re going, ‘God, I can’t wait ’til they get home,\'” says Shelton, 41, whose new album Texoma Shore hit No. 1 on the

Top Country Albums chart this week. “They’re so damn funny. It’s just my first time being around it, and it’s easy to fall in love with those kids. They’re pretty special.”

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WATCH: Kids Ask Blake Shelton What His Favorite Gwen Stefani Song Is – and His Answer May Surprise You!

As for his relationship with Stefani, 48, the power couple (who recently teamed up on the song “You Make It Feel Like Christmas” featured on her holiday album) are happier than ever together. Says the star: “It just feels like it gets stronger all the time, you know? It’s crazy.”

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