We can only be responsible for our own behavior because that's the only one we control. If others behave badly, they behave badly! We don't have to condemn them for it or get them to see it or anything; all of that is their problem. But we cannot take the "blame" for it either, that's not possible. There are no "excuses" for behavior. It just is. Behavior is always a choice of the person behaving in that way. You might want to start saying to yourself, "I choose to excuse my friend's behavior." At least then you will get it sorted right; you won't be judging him, it won't be bad behavior, just behavior that you do not agree with or like. It's okay not to like someone else's behavior! Judging someone else's behavior though is not our job, we have our own behavior we have to work with. Start putting "I choose" in front of what you are doing and it can help your thinking about things.

I choose to excuse my friends behavior.
I feel hurt by my friend's behavior (start sentences with "I" and then add a verb and you can't go wrong -- not the same as "my friend hurt me", that's making it your friend's "fault" you are feeling hurt when how we feel is all inside us, not other people out there).
I think my friend's behavior is not behavior I would like to emulate.
I choose to take a break from my friend's behavior for awhile (and then tell them you'll be back in touch when you are feeling better).