The institution of marriage was created in the late Neolithic era to protect women and children and not men. Men had all the power, including the power to murder his women and children, so men as a collective threw women a bone dictating that, if a man left his wife for whatever reasons besides cheating, that he should support her with an income for the rest of her life. This was obvious and necessary since women couldn't earn any income.
The problem is that, nowadays, women have as much if not more power than men, but the institution of marriage continues to protect women and children out of tradition. Men are screwed because the traditional institutions of society still see women as the weaker gender in need of protection. A man leaves his wife and he has to give her 50% of everything he has but if the woman leaves the man she doesen't need to give him anything. An adolescent girl committs an act of delinquency and she receives a slap in the wrist from the male judge since she is "one of the future mothers of Society and sending her to a brutal prison environment would ruin her nurturing instincts. An adolescent boy in the same position gets sent to juvy to be brutalized and "straightened into a man". Most boys get the prepuces of their penises hacked at birth and no legal consequences come from it, but if a doctor even pricks the genital of a baby girl, there is hell to pay. Boys learn from a very young age that girls get away with almost anything, whilst boys get beaten and straightened out if they do crazy stuff.