Have you tried having an adult discussion with the captain, in neutral setting? There is good chance he hasn't heard directly from his first officers in this manner. Most people try to avoid any direct confrontation, and just move on and use the avoid-with strategy. You are not helping anyone by doing that.

Many years ago I flew with one such captain on the DC-9. He was a big, body builder and came across as being intimidating before he even opened his mouth.

A few minutes into our talk, he broke down and told me no one ever talked to him like that. He really did not even realize why the flight attendants did not like him either. He did improve and actually put himself in counselling. ( which unfortunately he had to tell me all about whenever I flew with or saw him).

When I "told" him we needed to have a discussion, he first took it as a challenge to his authority. I explained that if we didn't, I would take myself off the trip. That worked.

Remember too that us captains have no way to bid around first officers. There is one that I told to put me on his "avoid" list. Haven't flown with him since- although flying with his wife was quite pleasant.