In a certain way, it does. As I was talking about the other day, the basic accepted morality of the Buddha's day was that you could have multiple wives. That's not usually accepted these days. During my younger days, living with someone before marriage wasn't considered very good and it was just coming into fashion. These days it doesn't raise an eyebrow. Values do change and so morality does tend to change, although what doesn't change is whether we are approaching our actions with compassion or not. So if we are actually doing certain actions through selfish intentions, being manipulative and abusive, then even if we are in a marriage situation it's not really moral. It really does come down to how we are approaching our actions, speech, and thoughts rather than the labels put on us or these types of things.