Zina is the most disliked act in Islam and is forbidden (haram). Prophet Mohammad (P.B.U.H) said that adultery is among the biggest sin. It is a shameful and evil act which leads to so many roads to other evils
In order to get to Jannah, a person has to make sure that he is the best to his spouse/Spouses. Do not shout at your spouse’s for mistakes they make. A Hadeeth says: “The best from amongst you are those who are best to their wives.”
Polygamy means the practice of having more than one wife or husband at the same time. Polygamy can be of two types; one is polygyny where a man marries more than one woman (man is allowed to have up to four wives), and the other is polyandry
Allah said that spouses are garments for each other and the purpose of garment is to protect you from harm similarly in the relationship of Nikkah both are responsible for each other's safety and protection.