One of the sweetest couples Hollywood ever produced. Jimmy Stewart adored Gloria. They had two children together and he adopted Gloria's two children from another marriage.
Newman and Woodward met on the set of the Broadway production of Picnic but they didn't fall in love until they played opposite each other in The Long, Hot Summer (1958).
While a lot of actors strayed, James Cagney never once cheated on his wife in the 6+ decades they were together. Not even Merle Oberon's advances could persuade him. In his autobiography which was published in 1976, he says
"I married her in 1922, absolutely the smartest thing I ever did in the whole course of my life, and I am still crazy about this lady."