Alice Cooper and Tiger Woods. (WENN.COM file photo)

Rock legend Alice Cooper feels sorry for Tiger Woods over his marriage troubles - he's convinced the disgraced golfer is simply "expressing his teenage libido" after spending his youth concentrating on sports.

The School's Out hitmaker is adamant he does not condone infidelity but admits he wasn't surprised after news of the sportsman's numerous affairs hit the headlines last year.

Cooper tells Britain's The Sun, "Tiger has played nothing but golf since he was five. He had no teenage life. Now he's a star, he's expressing his teenage libido. I don't know why he got married in the first place."

But Cooper has ruled out ever cheating on his wife, Sheryl Goddard.

He adds: "I've been married 34 years and have never cheated. When I got married I took the view it was for life. Why would you want to hurt her?"