Is it way, way off the radar to call a step mum 'Mum'

Well if it’s been going on for years there’s not much you can do about it now So that’s it the child has two mums

My step-children--adults now, called me by my Christian name but all their offspring call me nan.

I should add that he lives with his biological mother and her new partner, and the other "Mum" is his dad's new partner.

I don't think it matters as long as the child is happy. I had a arranged a playdate with a neighbour's little boy for my grandson when he visited recently and the child who came to play was happily talking about his "two Mums" which I found quite endearing and I thought what a well-adjusted little boy and well done to the parents.

Then it’s wrong Serendipity.

Sometimes young children will want to fit in to a step family, especially where the father is called Dad by his stepchildren, and will choose to call his wife/partner, Mum.

If everyone involved in the family is happy with it, I don't see that it matters. But I'm guessing that somebody isn't happy with it?

The child has been encouraged to call the step mum 'Mum' by the child's dad and its stuck every since ( for years )

Seems unusual but why do you ask Serendipity22 it would be helpful to know the context,

I have to say I would not like it. Everyone is different but it just seems strange.

Is it the child that wants to?

Wouldn’t work for me