Sister disinvites reader’s wife from wedding

DEAR HARRIETTE: I’m currently caught in a battle between my sister and my wife. My sister is getting married soon and, unfortunately, does not want my wife to attend. My sister has always been rather protective or defensive of me, but about a year ago, after taking a trip together, my sister decided that she thinks my wife is self-centered. At first, I laughed it off because I disagree. But throughout the year, I’ve noticed that they don’t talk much anymore, and my sister can be a bit unkind to my wife.