I CHEATED WITH DIANA ROSS!

POP star Smokey Robinson is dishing he plunged into a steamy year-long affair with Supremes beauty Diana Ross while he was still wed to his first wife, Claudette Rogers.

Now 83, the Tears of a Clown singer confesses the affair exploded during his 25-year marriage to Claudette, which ended in 1985, when he was trying to help Endless Love singer Ross “get her career together.”

Smokey explains, “She was young. I was married. I wasn’t going after her and she wasn’t going after me. We were working together and it just happened. It was beautiful.”

But guilt doomed the Motown legends’ forbidden romance.

“After we’d been seeing each other for a while, Diana said to me she couldn’t do that because she knew Claudette, and she knew I still loved my wife,” he says. “And I did. I loved my wife very much.” Robinson, who’s been married to Frances Gladney since 2002, says the affair taught him “we are capable of loving more than one person at the same time.”

Diana, who’s been married twice, hasn’t commented. But actor Warren Beatty, Kiss rocker Gene Simmons, actor Richard Gere, Michael Jackson and Motown king Berry Gordy are among the many smitten men who fell at her feet.