Blake Shelton says his relationship with Gwen Stefani is more ''shocking'' than him being named PEOPLE's Sexiest Man Alive.

The 43-year-old county star - who joked he thought they'd run out of people to receive the title in 2017 - has admitted that when he first met the No Doubt star as coaches on 'The Voice', they went for a long time without developing a close friendship, which is why he's so surprised that they became romantic partners.

Speaking to Martina McBride on her 'Vocal Point' podcast, he spilled: ''If you thought the People magazine cover was shocking, mine and Gwen's relationship is probably the biggest head-scratcher.

''I'll even say that she was, of all the coaches, the least that I had gotten to know the first season she was on the show because she had just had a baby, and I mean just had a baby.

''And so any time there was downtime, she was busy.

''She was gone, she was on her trailers, she was taking care of the baby, you know, and there was never those moments that usually happen on this show, where at the end of the day we're sitting around out here at the couches and having a drink, talking, laughing.''

By the second season of the talent show in 2015, the pair started dating after divorcing their respective partners, which is something they ''bonded'' over.

Gwen was married to Gavin Rossdale - with whom she has Kingston, 13, Zuma, 11, and Apollo, five - and Blake was with ex-wife Miranda Lambert for four years.

The 'God Gave Me You' singer added that ''a lot of life had happened and we'd been through a lot, and we bonded actually over that.''

Blake believes it was all ''meant to be''.

He added: ''And it's one of those things that, who knows?

''It had to have been meant to be.''

Gwen credited her beau with helping her to ''build [her] life again'' following her divorce.

She said recently: ''I feel as if I spent the last four years healing - you know, trying to build my life again.

''Having a best friend like Blake to help me do that has been one of the greatest gifts.''