Blake Shelton hates hearing about child-like Adam Levine's private life

Blake Shelton hates it whenever Adam Levine, his rival on U.S. talent show The Voice, has a new pet project - because he's unbearable for weeks.

The country singer and the Maroon 5 frontman have a love-hate relationship on the show, and Blake admits his fellow judge can be a real pain if he's passionate about something.

"Adam is a 14-year-old boy trapped in a 30-whatever-he-is body - and that includes his attention span," the Honey Bee singer tells Rolling Stone magazine.

"He's all fired up about houses he might buy: 'Hey dude, look at this one, check this one out!' It's just like, 'Oh, my God, man. I know you're not going to buy any of these'.

"When he gets on something, you need to take a (painkiller) Tylenol and get ready, because that's what you're gonna hear about for the next month. Before this, it was golf!"

Blake had better brace himself for what's to come as Adam will become a first-time father later this year (16) - the rocker's model wife Behati Prinsloo is expecting the couple's first child at the end of the summer.

And the two singers will also be back as foes and rival judges on The Voice later this year (16), with Blake still keen to take Adam down after the Maroon 5 star made his life hell over the Christmas holidays last year (Dec15) when his pick Jordan Smith beat Shelton's two contenders Emily Ann Roberts and Barrett Baber.

It was Levine's first win since 2013, and his third in total. There has been a friendly rivalry between the judges since the show started in 2011. Adam won the first season, while Blake hit back by emerging victorious for the next three consecutive seasons.

Now Adam has three wins to Blake's four.

Christina Aguilera became the first female mentor/judge to win The Voice when her pick, Alisan Porter, was named the show's latest winner last month (May16).