Blended families can lead to all kinds of unique and strange situations. Imagine being a divorced mom, and your kid spends half of their time with their dad, who has married a woman who also has children from a previous marriage. Their kids spend a ton of time together and have an established relationship, but you, as their other parent, know nothing about your child’s step-siblings. All you know is what your kid tells you, which could be limited depending on the kid.

If you extend the thought experiment further, you probably have never met the ex-husband of your hypothetical exe’s wife. Even with minor familial blending, there’s so much to keep up with that you can’t concern yourself with children who aren’t your child or your step-child. That’s plenty of responsibility for one person to handle, and overreaching is spreading yourself too thin at best and offensively overstepping boundaries at worst.