One way to prevent these moods, particularly bad moods, from escalating is a certain amount of tact. Candor can be vastly overrated in a relationship. I certainly don't mean the relationship should be based on dishonesty or deception. What I do mean is that candor often means being, as Cokie says, selfish, self-indulgent or hurtful. I thought it sounded rather unromantic at the time, but upon reflection, I really like it.
Romance is a wonderful thing.
I think it's very important. It's very important to keep romance in a marriage. If you can problem solve as partners, rather than setting up some sense of blame or competition, you're way ahead of the game. But that's not easy. Some of these things only come after years of acquired wisdom.