Unfollow him...You don't have to attend every argument you are invited to even if the person is dead wrong and stupid.
Everyone that knows him personally knows that he is lying to himself so it doesn't really matter. I was once with friends on facebook with a young woman who had her child at 16 and is now 22. She would post dumb shyt like, "Nothing is wrong with having a baby at 16"

"I hate Beyonce for lying to us about her pregnancy. That bytch needs to die" I don't care for Beyonce and even I was like

"Any bytch that come near my man already know that I'll step to her like a nikka"
Mind you her son was 3 by then and being exposed to her complete ignorance.
I unfollowed, unfriended, and blocked. She talked so much about gang shyt (her boyfriend and cousins were in gangs) and her spelling reeked of illiteracy . There was no point in speaking with her. Life would teach her a lesson
I saw her on campus and she wanted to invite me to her sons birthday party. I politely declined. I didn't want to be caught in some crossfire due to someone having a hit on her.