Blake Shelton admits his relationship with Gwen Stefani is "odd".

Blake Shelton

Blake Shelton

The 39-year-old country singer began dating his fellow 'The Voice' coach in the wake of their respective marriage splits from Miranda Lambert and Gavin Rossdale late last year, and though they are having "a lot of fun" together, the 'Came Here to Forget' hitmaker is aware he and the No Doubt frontwoman are an unlikely couple.

Speaking on 'Today', he said: "It's a little weird. We could not be, on paper, any more different. I mean, I'm a country singer and she's a ska, rock, pop, whatever it is ... and it's just an odd idea. But man, it's a lot of fun. I've gotta be honest about that."

The couple recently worked together on a duet, 'Go Ahead and Break My Heart' and Blake initially started writing the track to "impress" Gwen, 46.

He admitted: "I actually wrote that song, started it just to try to impress her, to be honest with you.

"I sent it to her just half done and said, 'I wrote a song, kind of about you,' and she wrote the next verse and sent it back to me. And so it was like, 'Oh, we've got a song together.' That's kind of cool."

The singer's new album, 'If I'm Honest' is largely inspired by his personal upheaval and he admitted he made a conscious decision to "cash in" on his life because there have been so many stories about him and his situation.

He said: "I figured because everyone else is cashing in on my life, I might as well too. So, that's what the record is."

Gwen - who has sons Kingston, nine, Zuma, seven, and Apollo, two, with Gavin - has previously admitted she never expected to fall in love with Blake.

She has said: "[He] had been going through literally the exact same thing in literally the exact same time frame.

"Never in my wildest, craziest dreams would I ever have seen this coming."