I'm going to out my closeted brother after he mocked me in front of my family and friends
Do you think he mocked you intentionally?
I know he was looking for an excuse to throw me out of his life even though he doesn't know I'm gay too.
It's understandable that you feel hurt by what your brother did. He should never have embarrassed you in front of others. However, you should talk to him first and not intentionally do something to hurt him back.
I don't care what people think of me. They can praise me or hate me. I was more pissed off that people think I'm not a good person for outing him because I am gay.
It is wrong to out someone if they are not ready to have other people know. Just because he hurt you doesn't make it right to hurt him back.