Saluki, porn is not a need. It's a want. Asking her husband to give up porn because it hurts her is not asking him to put her needs above his. It's asking him to put her needs above his wants, something that anyone in a relationship should do.
Second, it's not a double standard. I put my husband's needs first, and I expect him to do the same because we're MARRIED, and that;s what we both vowed to do. Putting his needs first DOES NOT mean that I have to be a doormat. It's my responsibility to speak up when something bothers me, and my right to expect him to care and want to help.
It is a red flag in ANY relationship when a person knowingly does something that is harmful to his partner for no reason other than his own wants.
Non-committed relationships (ie, just dating) are different. There are no vows to hold you in place. You are free to leave if something the other person does bothers you. This is not the case in marriage. You make a promise to each other to stick it out, and "just leaving" because a behavior bothers you is not always an option. Because of this, both the husband and wife are expected to do what is necessary to make it work. Giving up something unnecessary to keep from hurting your spouse is not only the best thing for the relationship, it is RIGHTFULLY EXPECTED of BOTH spouses.
It's not wrong or a double standard to expect that any person do what they promised to do.