Every MAN knows that he should come to a woman's defense if there's another man abusing her.
It's the same thing.
If I see a straight person abusing or bullying a gay person, it's my DUTY to step up and speak.
If you're in the "privileged" group, you should be working to help the other, and this story demonstrates it wonderfully:
I found it at UPWORTHY: One Easy Thing All White People Could Do That Would Make The World A Better Place:
'via Blog this'