At the beginning of III Johnny Fontain starts his act and Michael conspicuously gets up to leave the room. Johnny seems
miffed and says he is going to sing Michael's favorite song, to which Michael makes some kind of obscene remark about a salcice, and then says he is oging to listen to his Tony Bennet records. Why this insult? What did Johnny ever do to Michael? Was this simply a device to show how cold hearted he was? Or was it more sloppy writing used to fill time?

Not sure my memory is on as I have not seen the film in a while, but maybe it could be to contrast how happy the Don was to see Johnny in GF1 and how different the two men were, Vito surrounded by his sons and old friends as capos, and Micheal who has killed or alienenated most of his close associates except for Nieri....

Ofcourse Michael wasn't serious when he made that remark. He just had some business to attent to. We all know Mike wasn't exactly the party type...

Yeah, it was just a kind offunny line about going to the kitchen for a salsicci sandwhich. But keep in mind that where he ends up is talking to Kay for the first time in God knows how long. I think that's why he left the main room as Johnny was about to sing a song - to see Kay.

I think it was a directorial device: FFC was introducing us to all the folks we knew and loved in GF and II, and wanted to put some repartee twixt Johnny and Michael to show they were still pally (and so Al Martino could have a little dialog as well as a song). I didn't see it as an insult. Tom served as the punching bag for Michael''s real insults.

I might be reaching, but maybe Michael resented Johnny a bit for being more legit than he ever was. But overall, I agree it was some lighthearted ball busting on Mike's behalf.