"I am actually proud of the "double standard." Wish it weren't so, but glad to be on the side of right."
Exactly. But don't think about it as a double standard. Think of it as an issue of ethics and the existence of moral reasoning. Others choose to operate without the simple acceptance that good is constant.
Good point.
In fact, I explain this to my kids all the time, saying "don't worry about what your brother is doing; worry about your own conduct and doing what you know is right"---when a correction to one is immediately met with a "but he did x, y, z!"