I'm going to ghost a guy for the shit he posts on social media.
What upsetting things does he say on social media?
He contradicts himself all the time. He's selfish.
I'm sure it's difficult dealing with someone you don't like, but you still shouldn't ghost them. If you don't want to talk to them anymore, explain how you're feeling. Otherwise, they will be hurt and confused at your suddenly abandoning them.
I don't care.
You should care because he's going to annoy you more. If you tell him straight that you don't want to hang with him anymore than he is more likely to move on right away.