What do I do when my brother puts that I was a faggot in his Facebook?

Faggot is a very offensive word and your brother is an asshole for using it in the first place. There's nothing wrong with being gay.

You must be literally 13 because this is not something that would concern anyone over the age of 13. Be confident in your sexuality and don't worry about what people will say/think. The people who actually matter will know the truth about you and that you're not gay.

**Edit: just checked your perfil and it says you're 13. I was spot-on about your age. Props to me for being right constantly.

Wow. Your brother is a fucking asshole for doing that. Like sarabeara said. Be confident in your sexuality. Don't care what other people think. I know I wouldn't. If they don't like you for you then fuck them. Because that is exactly what I'd do. I'd either do that or not talk to them at all. Your brother needs to take other people's feelings under consideration if he doesn't that may come back and haunt him.

Well isn't that rude, I don't really think anyone will say anything about it but I'd ignore it. Sorry if that's not enough, I could really careless about what people think.

Ignore him. Sibling rivalry, it happens. I say suck it up, that stuff goes on on facebook everywhere every five minutos and nobody cares.

You know what? You shouldn't care. There is nothing wrong with being gay and you shouldn't feel insulted. If kids at school react, explain calmly that you and your brother had a fight. If they react badly, it shows what type of people they are.