I'm trying to avoid someone I use to be friends with but recently came back.
Did he do something to you?
He's too petty and he makes putting up with him painful for me
I say keep avoiding him if he's that way. Not to the point where it becomes uncomfortable for you, but just do your best.
He was a friend but he was mean to others, I got tired of having to deal with him.
Nobody is forcing you to spend time with him which is good. You are free to choose whomever you would rather spend time with.