His life was their life until he fell in love with you. Don't let them ruin your future.
With a partner be allies, the intrusive behavior of the mother-in-law and father-in-law must not lead you into conflicts, alienation and loneliness. Set boundaries for them! Toxic people only have power over you if you let them!
If your partner's parents are toxic, you have only one option to save the relationship. Insist that your partner talk to them and sets boundaries for them in relation to you and your life. If your partner thinks that this is your problem and does not want to interfere, you will distance yourself more and more from him and the conclusion is in the palm of your hand, your relationship will end.
So when should you pay attention to the behavior of your mother-in-law and father-in-law? Are your partner's parents behaving in any of the following ways?
They interfere in your life
Over and over again, they give you unnecessary advice about raising children, tidying up the apartment, wardrobe - about anything they can think of. You accept the fact that these are your partner's parents, but that doesn't give them the right to interfere in your life, especially if they keep criticizing you.
They belittle you and your decisions
Whatever you do isn't good enough, and they point that out whenever they have the chance. And this regardless of whether there are other people around you, maybe even your children. They never help you, they just look for opportunities to ruin your day.
They hand you a list of rules to follow
Otherwise, they punish your partner. This is abnormal control and is something you should not tolerate.
They have a strong influence on your partner's decisions
As an adult, you are responsible for your own life. Parents should not even try to influence decisions, let alone make them on behalf of their adult children.
They start fights over small things
They are just looking for a reason to fight to bring conflict into your relationship. They always blame you for the fights.
They require you to ask their permission
For example, if you can buy a gift for your partner. They want to have complete control over his life. They act as if he is still a small child and they know best what he needs.
They have control over the partner's daily activities
Always for every hour of the day, where he is and what he is doing. Do not allow such manipulation.
The only solution, to maintain your relationship, is for the partner to put the parents limits and ultimatum: either they will start behaving differently or he will break off relations with them. Usually the parents are offended and won't talk to him for a while, but eventually they will in all probability discounted! But they will never admit that they did anything wrong.