I think it depends on the age of the child. I never taught my sd what to call me. She eventually chose to call me Mimi. Once we were married she chose to call me mommy. If I had come into her life later she would have only called mw by my name. Upon marriage it would be nice if it was modified to mommy lindsay because as a step parent I think that my title needs to remind the chi ld of the respect I am owed in that position and that I love her as a parent.
my dd is 2 has seen her dad once, his family had nothing to do with her.
My bf now said he's willing to adopt if we marry. She will call him dad. He said that's what he wants to be for her is a dad. He said not right now, but eventually he'd want to be called dad.
My kids don't have a new dad. Kids have one mom an one dad. They call my SO by his name. I could see if step dad came around when they were babies an bio dad was totally absent but I also make sure my kids knew that this was not their bio dad. I think lying to kids is hugely fucked up. I know a couple guys who grew up thinking their moms partner was their real da and did not find out until nearly adult and let me tell you it rocked their world. People deserve to know where they come from even if its less than perfect.
Sorry for The rant, I know that was t what you were specifically saying.