Are any of you perfect? Have any of you done things that may have been considered out of order? I’m pretty sure I know the answer.
Who said they were perfect? Do you think the people who agree with you are perfect?
Non of us are. I am also sure that some people may not be happy with everything I do. However, I haven't lost my shit over fish and chips and alienated my MIL. I don't even like my ex MIL, or my dps step mum. His mother left when he was a baby, so I have never met her.
However, i appreciate that a grandparent, will spoil a child a bit. They will feed them some rubbish. I also would expect to to side with his step mother if I went Batshit crazy with her over something small. Of went round and removed my child from her house.
You get on with MIL 95% of the time but are sick of her over baring behaviour. It doesn't even make sense. You know you were unreasonable. I think you know you are in general.
I mean this next bit kindly, because I genuinely feel that your son is your son. Do you think that somewhere you resent that she has been in his life longer than you. Do you perhaps feel that because you are not his birth mother, you feel you have stamp your authority with MIL more.
Because, let's be honest, there is no way you could have possibly though that going and taking him home was reasonable behaviour.