The lovable next door neighbors/landlords on I Love Lucy could not stand each other when the cameras were off. They were said to insult each other constantly and could barely be in the same room together.
When William Frawley (Fred) died in 1966, Desi Arnaz (Ricky) paid for a full page ad in the Hollywood Reporter about his passing. Vivian Vance (Ethel) allegedly said “Champagne for everyone!” when she heard the news.
Something else you might not know about I Love Lucy is that Lucy was a very professional woman and could be rude sometimes. When Vance was late for a cue onstage, Lucy was quoted insulting her and calling her promiscuous.