Unsure where we are going

[Traveler]

I understand that they both had bruises, although I saw the photos of hers.

Huh?! If she's physically abusing your son, taking action would be a great 180.

Tonight he was acting up a bit, whinging about going to a certain Mcdonalds when she wanted to stop at a different mcdonalds. She threatened him with not organising his party for him. I thought this wasnt right, but didnt mention it. In last times that would have ended in an argument both about the party and about the mcdonalds.

Yes, I can see controlling behavior (telling her what she should or should not do) ending in an argument. You control you. She controls her (as long as she isn't abusive). Good job!

Instead I said told him to not worry as all Mcdonalds are the same and the particular Mcdonalds you are going too is not something really worth fighting over (the second point was really addressed to the wife). Everyone calmed down and we went to McDonalds in peace.

I wonder if you see the opposite of arguing and controlling her (aggressive behavior), as doing what she wants (passive behavior)? Obviously, not all McDonalds are the same or your wife and son wouldn't be disagreeing about which one to go to. WHOSE McDonalds did you go to in peace? This exchange isn't a big deal, but note favoring one over the other also isn't a big win for dealing with conflict or teaching your son how to deal with conflict. Happy Meal food for thought.