I have a really hard time dealing with this guy who is immensely socially awkward
Is this something that he does all the time?
Yes, quite often.  Even before I met him. He makes fun of people to their face quite often. He isn't aware when he is doing something socially incorrect
You probably feel so uncomfortable when he acts inappropriately, but you should be patient with him. Try telling him politely how his behavior offends you.
I don't really care. I've expressed my concerns to him before and he took it personally in a bad way.
I'm sorry that happened to you. You should try and be patient with someone who is socially awkward. Give him more time and work with him to improve.