Reminds me of a work situation many years ago. There were two fellow (A & B) who didn’t get along and got into another disagreement one day. A ended it by telling B as far as he was concerned B didn’t exist anymore and walked away. There were times when B would ask or say something to A and A would act as if B was not there. There were a lot of bets as to when the foolishness would end (never did). Fortunately for both, they never worked on the same projects together. A totally ignored B until A left the company about a year later.
Mick & Mason Mastroianni
Parker and Hart