Blake Shelton admits that when he and Gwen Stefani started dating three years ago, he didn't think it would last. Stefani would probably say the same thing, he says.

During a preview of Shelton's appearance Sunday Today with Willie Geist (airing June 24), the "I Lived It" singer admits he was at rock bottom while going through his divorce from Miranda Lambert. It was a miracle, Shelton feels, that he met someone going through the exact same thing.

"I think in the back of our minds we both kind of thought this is a rebound deal, because we were both coming out of a pretty low spot in our lives and we’re kind of clinging to each other to get through this," he says in a clip from the show. "But now here we are, going on three years later."

"Every day that goes by just feels like a stronger bond between the two of us," Shelton adds. "It constantly feels like it’s going to the next level."

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Both Shelton and Stefani have talked in lose terms about getting married, but there's been nothing to indicate a wedding is in the immediate plans.

Shelton sat down with Geist at the new Nashville location of his Ole Red venue. The interview comes less than a week after Shelton's 42nd birthday. Stefani got her boyfriend a flagpole for his ranch and then shared some photos from a day on the lake.

The pair met in 2015 when both were coaches on NBC's The Voice. Stefani was previously married to Gavin Rossdale. Shelton and Lambert divorced in July 2015.

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