I have a 19 year old son who sometimes clashes with his step-mom. They used to get along, but my wife has made it pretty clear to him what she wants and doesn't want around the house. Often my role as dad has me caught in the middle. I'm pretty sure he doesn’t want to get his step-mom anything for Mother’s Day. I don't think she expects anything from him, but I do...am I right or wrong?

Must my son take the high road and and buy his step-mom something for Mother's Day? Does a card suffice? Should I insist he takes "the high road"?