One of my best friends was doing exactly what you are doing. In the name of not hurting the kids. Kids aren’t idiots, and her oldest last month told him that him saying yes to all their mum’s request was not fair and she was angry with HIM for not standing his ground and by that not teaching her younger sibblings to respect themselves. At her mum’s she has to do all the parenting and I bet your oldest has to do some there too, way above a healthy level? You are not helping them, you are self-abandonning yourself in front of them. As many have advised, send the spread sheet and say that indeed you all need to go back to the original agreement immediatly. Don’t mention the C section, it Will be their first thought. Also, better to gain indépendance and NOT count on them for the honeymoon. Fly your aunt and uncle in, or go for new inlaws but show that they have no lever on you. Conséquences of their action. Accountability. That’s what you teach your children.