How I get referred to is something we are still working on. We don’t refer to me as Mum when my wife is around as she doesn’t like it. If she’s not around then I become Mum if we don’t think there’s the need to explain the complexity of our relationship, otherwise I’m introduced by my name or in circumstances where out biological relationship could be important, such as in hospitals, then I’m introduced as Dad.
At one point we did introduce me as “not the Mum” but that hasn’t happened for a while.
I’m sure that we’ll eventually figure out some way of referring to me that will show the relationship between my son and I without us having to explain to people that really don’t need to know the ins and outs of our personal lives.
One thing is for sure though, no matter how he refers to me I’ll always be his Dad.