All schools are like that these days.
I think it's generally because 'tougher' boys tend to be the people who think they rule the year and if a boy doesn't act like them they see them as being gay. It's just down to ignorance and age really...whether they really mean it or not, there's a bad stereotype of homosexuality in schools these days. As long as they aren't violently bullying him, I can understand why he chooses to laugh at it all. :P