TIFU by fighting with three diffrent friends because I can’t recognize a walking red flag

So, for context: I (16M) am bisexual.

Today, since one of my classes canceled, I found myself talking to a not-so-close friend of mine (let’s call him Lee) who is infamously very rude and stupid, but I accepted this since this behavior is sadly quite common where I live. He started the conversation by asking me about my romantic life. I told him I don’t have any, since I have too much work to do. He asked me how does it feel, being gay. I told him it’s great. He asked me how do I know if someone is gay, so I explained what gaydar is. During this conversation, he also introduced me to his friends.

Then, a classmate of mine, (let’s call her Rachel), walked by. I greeted her with “Good Morning”, she ignored me.
-FIRST RED FLAG-
He quickly jumped in, and was close to yelling at her for not greeting me back. I had to restrain him. She walked away.
-SECOND RED FLAG-
I later found out that he used to bully her.

-THIRD RED FLAG-
Out of nowhere, this guy starts talking about conversion therapy. He asked me what are my thoughts about that, and I told him I was against it. While I explained the abuse that is going on in these “therapy sessions”, I saw him kinda getting horny on the idea of electrocutingraping homosexuals. He told me about his cousin who was gay until having a conversion therapy, and even recommended a specific religious leader who is an expert in conversion therapies with no abuse.

-FOURTH RED FLAG-
Another one of his friends joins in, and he asks me to explain again about conversion therapy, including that part where it makes people commit suciide. His friend kinda gets horny, too. We keep talking,

-FIFTH RED FLAG-
He starts talking about how he wanted to put a math book on my back and solve questions while fucking me in the ass. I started getting really uncomfortable.

-SIXTH RED FLAG-
Another friend (16F) of mine walks by. Lee startes talking about how he wants to electrocute her to death because she’s trans (She isn’t, btw). She looks at me and tells me to stfu. I tell him that, too. I end the conversation there.

I proceeded to block him on every app available, and I plan to yell at him in his face next time I see him.
Both of the people he insulted are now mad at me for talking to him in the first place.

TL;DR: today I fucked up by starting a horrible conversation with a friend (now ex-friend) of mine, who made violent threats towards my friends and sexually harassed me while getting horny on sadistic abuse of minority groups.