This does not surprise me. Why? Because we all have an incredibly powerful force driving us towards self-righteousness. We judge the Pharisees but fail to see the "logs in our own eyes." Marriage (or co-habitation) provides a great feeding ground for self-righteousness. (My family also pointed out that teenage-parent relations are another forum). Life-style issues relating to reducing our environmental impact are just another battle ground...
God has placed within us a strong desire to be right. But we pervert this by trying to establish our righteousness in comparison to others unrighteousness. But the only way we can be right with God is if we accept his gift of righteousness provided by Jesus. (Romans 3:21-26).