Justin Bieber will take a stand against bullying and homophobia after he was on the receiving end of some hateful words this weekend ... TMZ has learned.As TMZ first reported, Bieber was confronted by a 12-year-old boy at a laser arcade -- and things got heated after the boy called Bieber "a fagg0t." We're told the boy repeated the comment and then put his hand out toward Bieber and Bieber pushed