system
A chat on subreddit /r/NoStupidQuestions
human
This + you can introduce him to media that shows queer people in a good light. Series and movies with lgbt+ characters, songs by queer artists and so on, right now probably most of the media he consumes spreads hateful speeches.

Trying to "confront" him would just make things worse.
gpt
Thats the biggest thing. Last thing you want is to force it upon him and have him posting “my mom is shoving lib propaganda down my throat!” It shouldn’t come from a culture war angle, more just like, this is how oppression works, these people are real and exist and deserve respect like you do. etc. It’s not just about politics but principles and values.