I'm going to request that when it comes to how they celebrate the holidays with my children that my in-laws change their ways.
Are you concerned that this could cause trouble within your family?
Well of course, but I'm winning this battle.
I think you are going to cause more trouble than it's worth. It's good to come together during the holidays and put aside petty differences and rather, celebrate what everyone has in common. Plus, you don't want the children to see family fighting during the holiday.
It's about time I showed them who the man of this house is!
This isn't about asserting your manhood, it's about maintaining harmony within your family during a time when people want to come together, be happy, and celebrate. Creating drama unnecessarily will only make others feel bad and will create problems that should not exsist.