The three of us walking around as a happy family is a public statement of commitment, no? When we were at Walking with Dinosaurs yesterday morning, no one questioned any papers or marital status. In fact there were thousands of people there, certainly a more truly public statement than hand-picked relatives & friends who feel compelled to show up for a plate of free food and booze.
It would cost time and money for something none of us care about. We'd rather spend our money on winter family holidays or finish off the new kitchen or new pool deck or just put extra into our daughter's education fund (which is appreciable already).
Not arguing, just pointing out that people have different priorities.