Although this is not very common, some couples choose to move away from the tradition where the wife adopts the husband's last name. In one case I'm familiar with, the host of a film review podcast I listen to got married. He combined his name, Sam Hallgren, with his wife's name, Carrie Vandehall, and they now have the common last name of "Van Hallgren". Here's how he explained it on his blog:

When Carrie and I first started talking about marriage last fall, I told her that I personally felt uncomfortable with the idea of her changing her name. Not because I didn't want her to take my name, but because I felt like the whole notion of a woman automatically taking her husband's name was a pretty archaic concept. But we talked more about it and we decided we really wanted our family (if/when kids came along) to have the same last name. Mom, Dad, Kids and Pets. The whole family. Same last name. So Carrie was prepared to become Carrie Hallgren. And then this Spring we were joking about combining our names. Just kidding around. Sam and Carrie Halldeest. Carrie and Sam Deestvanhall. Sam and Carrie Vandehall. Carrie and Sam Van Hallgren-Deest. Sam and Carrie Van Hallgren. "Wait a minute," we said. That sounds pretty cool. Sam and Carrie Van Hallgren. Like "Van Halen" but "Van Hallgren." "Why not?" we asked ourselves. Carrie gets to keep the "van" handle that she grew up with, and I get to keep "Hallgren" unsullied.

Here's a USA Today article from last year with interviews from other couples who have done it, including one husband who adopted his wife's full last name.

There are many reasons a couple may choose to do this. Maybe his wife is a devout feminist and wants to keep all or part of her last name. Maybe they're both irreverent and they want to thumb their noses at tradition. Maybe they want to do this as an expression of their love for each other.

The key question you must ask yourself is this: regardless of their reason, is it worth all your pain and worry, and the risk of jeopardizing your relationship with your son, just because he chose not to follow an old marriage tradition?

It's really not. He's your son. You'd still love and accept him even if he decided to have a pagan nudist wedding.

On a related issue, you said you were embarassed and humiliated, and that you think about it all the time. Did those feelings come out in your e-mail to them?