Just been browsing around on here, as you do, and read a couple of threads where the step child's mother was referred to as being their "birth mum". It wasn't being used in the context of adoption or in a situation where the mother has no contact with the child. It was used by stepmothers discussing their partners ex.
Am I being unreasonable to be offended by this? It makes me feel a bit angry to think one day by ex's new partner could be describing me as my daughters birth mum. I'm her mum, plain and simple!