WORLD EXCLUSIVE - John Wayne Cheated With Married Lucy!

Cowboy legend Jon "Duke" Wayne and America's favorite redhead Lucille Ball had a torrid 24-year love affair - while they were married to other people!

Now, in a sizzling world exclusive, GLOBE rips the lid off Hollywood's best-kept secret as a Wayne family friend dishes all on the forbidden fling. 

"They were very much in love, but the timing was never right for them to marry," the friend says. "I've Kept their secret for decades, but the truth must be told."

Get the scoop on this torrid affair between the two iconic actors in this week's GLOBE Magazine available on newstands today!