Exactly so.
My stepchildren's mother was a big enough woman to realize she was in a place where she couldn't give their children what they needed.
So we moved into her house, her dog, her kids, etc., for 7 years. When the kids had proms, graduations, etc., I invited her over to help her daughter get ready for the big night(s), take pictures, participate in the parties, and bring her mother.
We were both confident that the kids loved us in different ways but felt secure with us and safe in knowing that we all loved them.
Some very insecure people obviously don't feel the same way, and it's the kids who are hurt in the end.