the_leander wrote:
I've tried correcting him (something his mother refuses to do) but to no avail.
I honestly don't know how much more I can take before I crack on this.
"Dad" is a title you earn with interaction time. You must ignore the insults, and visit and interact with your son regularly to become "Dad".
Look at the reality of divorce. The mother gets to raise the kids. The father gets VISITATION. That means you spend some time entertaining and interacting with your son when you visit. The reality is, it is very emotionally painful to be just an intermittent visitor, for both you and your son. If you don't visit regularly, your son will have feelings of abandonment and rejection.