But if they couldn't work it out, remember that wives and girlfriends may come and go, but moms - and daughters/children - are forever.
I'm sorry, but I think this part of your advice was, frankly, terrible. Yes, okay, girlfriends may come and go (although they will go much more quickly if Mommy is taking first priority in the relationship
), but if you go into a marriage thinking that your wife is disposable and your mother is not, you might as well go right from signing the marriage certificate to drawing up the divorce papers. When you get married, you break apart from your parents and form your own family unit. This isn't to say that your parents aren't your family anymore (they are, of course), but you have now formed (or at least started to form) your own immediate family, and that family has to start to come first.
Again, the mentality that a wife is temporary and a mother isn't is just setting yourself up for problems of epic proportions.