How does it affect you .... ???

Is actually quite a selfish argument. Someone is trying to force you to argue from the standpoint of selfishness (What does that have to do with me???) How does the gay man that wants to get married affect me?

True love for every person cannot let you live and commit evil. Your good is my good. If I love you, whether you live in this country, or across the Atlantic, your concerns are my concerns. Argue from the point of selflessness, instead of their suggested selfishness.