How can you handle the fact that you are almost willing to cut ties with a longtime friend, with who you had a toxic friendship, but you are in the same group of 4 friends?

We are a group of 4, this guy sometimes acts like a best friend, sometimes he switches and he’s an asshole.

I never have conflict with non of my friends but with him. One of the reason could be we know eachothers from very very long time, he’s 3 years older than me.

Since he was a kid he kinda had a bit anger issues, was a borderline bully who tries to intimidate people (even if now we all grew up so doesn’t really work) and acts like a fucking child sometimes.

He has issues. Sometimes though as i’ve said acts like a super best friends, gifts you things etc.

But i struggle handling these “switches”.

I don’t know if it’s because we see eachothers many many times, maybe he’s the friend i see more and it happens that you have enough of someone.

But i don’t know what to do. I feel sorry for the other 2, seeing eachothers not talking anymore, maybe feeling they have to choose.

If he proposes to go on a vacation together, i won’t go since it’s a risk to go on a vacation with someone you have a shaky relationship since you are stuck with him for 5-7 days.

What would you do in my position? How do you end a longtime weird/toxic friendship?