I was staying with my in-laws when I had my firstborn. My pils behave just the same as your fil. We have talked to them several times but to no avail. They insisted they are my pils and they can do whatever they want as it is their grandchildren. Eventually, we move out on our own but the issue never stop there and continue. Long story short, due to their selfishness my girl's health is affected. She has asthma due to them smoking in front of her and giving her food she is sensitive to. We brought her for allergic reaction test and got report to prove that. They still go ahead to do what "they know best" than PD.
Ask yourself will you be able to forgive yourself when your child's wellbeing is affected? If you can't, I suggest you talk to him and tell him out front if he can't respect you as Mom you need to find alternative caretaker who respect your decision.
I regret my decision to respect and maintain the so-called "relationship" and cause my girl to suffer for life. I will stand up for her if I can turn back my time. Also, if he can't respect you for the smallest thing like feeding. You can foreseen a bigger issues in the future. Trust me, if you get pushover once it is hard to get the right footing in the future anymore.
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