Though they made quite the duo on screen, Bud Abbott and Lou Costello were frequently at odds with each other when the cameras weren’t rolling.

The two were known for their work in films like The Naughty Nineties (1945) and Abbott and Costello Meet Frankenstein (1948). However, during the filming of their 1946 film, The Time of Their Lives. According to the film’s director, Charles Barton, Costello became concerned that Abbott had a larger role in the movie.

“Lou called me one night, mad as hell,” said Charles Barton, according to Abbott and Costello in Hollywood by Bob Furmanek. “He wanted to switch roles with Bud. I think Lou had been off for two or three days, and he thought we were shooting a lot more with Bud than we were with him, because he never read a script. Neither did Bud. Anyway, Lou wanted to switch parts or else he was not coming to work. That meant scrapping weeks of footage. So we just sat and waited him out. When he did come back, everything was beautiful sailing from then on.”

On the other hand, Costello became concerned with the “new direction” the duo’s films had been heading toward. Though the two were well remembered as partners, by the 1940s, many films starring Abbott and Costello began focusing on them as two separate characters rather than a pair.

“Bud didn’t like doing them at all,” said Norman Abbott, the actor’s nephew. “He felt that Lou wanted to go on and be a different kind of comedian, that he didn’t want to be a team anymore. So the parts were written that was in a couple of pictures, and it didn’t work. The audience didn’t want to see that. They wanted to see the comedy team they knew and loved.”