"The relationship between mother-in-law and daughter-in-law" is a very sensitive topic for those who have entered the institution of marriage, often treated as a deeply taboo subject. One could say, among the many factors that affect marital happiness and family harmony, the "relationship between mother-in-law and daughter-in-law" ranks just behind infidelity as a "killer" of spousal affection. Some people even jokingly refer to it as a "malignant tumor" impacting the quality of marriage, and cite it as a cause for conflicts within the family.