Here Paul contrasts the virtue of love with the vice of 'bitterness'. The Greek term means to be angry, harsh, caustic. It speaks of a leadership which is domineering, cruel, without mercy or compassion, tyrannical. Conversely, bitterness in the husband will be evidenced by selfishness and a neglect to nurture the well-being of his wife. The immorality of this perversion is its violation of the sixth commandment.
Bitterness promotes death in the marriage.
It is found in that angry man whose words cut like swords, whose insensitive demands squelch the vitality of affection and hurtfully inflict pain upon his wife and children. This vice is often indicative of fundamental immaturity. He is an angry little boy in a man's body, conducting himself like a petulant brat who gets some morbid satisfaction out of just being nasty. The immorality of effacement also violates the sixth commandment in the same way that suicide violates the sixth commandment. It too brings a form of death and destruction into the marriage.