“ZORRO, THE GAY BLADE” star reveals senses-shattering SECRET as famed “Tan Man” GEORGE HAMILTON admits he’s no longer a serial cheater – because he’s TOO old!

At 72, the debonair ex- “Dynasty” star – who’s been with gorgeous German phy­sician Barbara Sturm, 39, for four years – confessed that he finally gave up his wicked ways because they were just too tiring.

“I honestly don’t cheat any­more. I’m too old!” Hamilton recently told an interviewer.

“First of all, it’s difficult to re­member all those lies, especially at my age. Second of all, the last thing I want is to have my wom­an leave me now.”

In his heyday, the dashing actor dated screen goddess Elizabeth Taylor, numerous beauty queens and Lynda Bird Johnson, daughter of then-President Lyndon Johnson. In the ’70s he mar­ried and divorced leggy blonde Alana Stewart, mother of his son, actor Ashley Hamilton.

“George was an in­credible lady-killer in his day,” an insider told The ENQUIRER.

“Women were drawn to him like moths to a flame, and he was always more than happy to oblige.”

But when asked if it was tough to be monogamous now, the “Love at First Bite” star laughed.

“No. Not at 72,” he re­plied. “It’s pretty easy. It was hard at 22, 32, 42, 52 AND at 62.”

The source added: “George has finally faced the fact that the odds of carrying on multiple affairs at his age are definitely not in his favor.  But his good looks and charm certainly served him well in his day.”