"This was attributed to her vocal resentment of having to play wife to a man 22 years her senior, which she took as an insult. When he got wind of it, it offended him so much, he never forgave her."
The fact that Fred was a mean, nasty, drunk of a man did not help the matter in any way.
"By almost all accounts, Frawley's off-screen personality was not much different from his on-screen demeanor. A notorious misanthrope, with one brief failed marriage behind him and a fondness for the bottle,[citation needed] he lived in the same bachelor apartment most of his years in Hollywood"
The fact that Vivian Vance was a b*#ch also fueled this fire.
Upon hearing that Frawley had died Vance had one thing to say...."Champagne for everybody!"
https://en.wikipedia.org/wiki/William_Frawley
