We have this dynamic where my mom cheated on my dad and is still with her AP. My dad is remarried to someone who he met later. And she's always insisting that we're a happy modern family and that these things "just happen in some families" and that she and my dad's wife are friends, etc. Meanwhile, my dad's wife does not like her and will sh*t-talk her to anyone who will listen, including me. My mom is always offering to come over to my dad's house for dinner-- that's right, she's inviting herself-- so that she can "spend more time with the kids", even though the kids hate dinner and sit at the table for max 10 minutes.
If I object to any of this, decline to validate her beliefs, or show any sign of stress while traveling with small children, I'm "carrying negative energy". So that's what I'll never do to my adult children.