In some families marital conflict is denied but gets expressed against another family member, often the oldest or the second child. The husband's shame may get turned into self-righteous wrath with the son. And, in fact, the problems of a two-career marriage without children would be quite different. But, even though financially better off, the dual career family has its own unique problems. Arguments over money may really be about who has the most power or about not getting enough attention or recognition.
All close relationships experience some friction.
No thinking person will always agree with us. The thrill of being with your lover wears off. Certain wishes and dreams about marriage will not come true. Criticism and resentment tend to be expressed in irritating ways. It is frustrating when we can't understand why someone does what they do.