United Kingdom, Dec. 14 -- Neil Diamond's wife is his "best friend".

The 84-year-old singer married Katie Diamond in April 2012 and the 55-year-old talent manager believes the "secret" to their happy relationship is supporting one another through all of lifes ups and downs.

Katie told People magazine: "We're best friends, and we really support each other. We lift each other up, and through thick and thin, through sickness and health, we really live it. And I think that that's the secret.

"And it's our 14th wedding anniversary coming up in April."

But the couple don't feel the need to mark their wedding anniversary in a particular way because they try to "celebrate" their love on a daily basis.

Katie said: "I mean, every day we try to...