Cutting a friend off

this is just my opinion but the way i see it you dont need to cut him off if he hasn’t actually done anything wrong, if you’re feeling unmotivated and unambitious thats coming from you because he cant control how you feel. if you are feeling unambitious that is a problem but it isnt a problem anybody else has caused.

He has done something. He has become insufferably obnoxious and keeps calling me stupid and being childish. He also gets angry at my other friends for no reason at all.

I'm not sure if I should associate with one of my friends anymore because, as bad as this sounds, they are ridiculously unintelligent and I'm worried that it's affecting me. I go to the gym with them every day, they have no GCSE's, no ambitions, no plans , talk like a roadman and when we asked him how to spell fur (just to see how bad it was) he said f-i-r-e and he wasn't joking. We know he doesn't have any learning disabilities; he's just been lazy for years. He constantly says stupid things and I feel as though his lack of ambition is rubbing off on me. As brutal as this is I think I should cut him off but want others opinions first.