Aibu to think it’s a bit early

[Dryrot123]

To be using ‘step-brother’ and ‘step-mother’?

I have separated from my husband. We are yet to be divorced, it has been a little over 15 months since the separation and exH has just moved in with his new partner. They have been together for less than 9 months. My DC has come home talking about her step-brother and step-mother.

Obviously for stability’s sake I hope exH and his new partner remain happy and together but isn’t it a little early for this language? DC still periodically upset about our split and finding getting used to ex’s new home quite difficult.

I agree. I think it is really good if your children have a positive relationship with their dad's new partner but I hate the term stepmother/father. They infer parental rights and responsibilities that an ex's new girlfriend or boyfriend simply don't have.

If i had my way "step" would only be used after the death of a parent. Otherwise they are simply someone your parent is married to.

I would let it go.
My ex encouraged his OW to get my DD to call her mummy. I had only just left his house. Very poor taste. Was done to hurt me.
Talk to your kid, explain how blended families work, and make sure they know they don't have to call the other person mum or stepmum, its usual to use the first name.
My eldest calls my OH his name, my youngest calls him dad. Youngest doesn't have another dad anymore so its natural for her. Eldest does and prefers to call him his name.