The only most effective thing you can do is to communicate. You can have an effective conversation with your wife too about this matter. Try to ask for advice from her as she is the daughter of your in-laws. What your in-laws are doing is completely wrong and you should stand against them. Your in-laws should have a justifiable reason for their doings because abusing their son-in-law is not right. Therefore, you should talk to your in-laws about this matter and ask them to stop this kind of behavior.