I was 28 when I got married and well established in my own identity/life. I did not change my last name and James completely supported that. Our son has my last name as his middle name. James gets called Mr. Beau from time to time and has no problem with it. He's confident enough in himself as a man that he doesn't have to resort to patriarchal control mechanisms to shore that up.
Although I also support people calling themselves whatever they want to, I also super hate the Mrs. John Smith thing. I even wrote something about that a while back.