I say Dad as possibly more likely then not hearing from your Mum (maybe)?
I am in my early 40's, Parents divorced and remarried when I was early 20's, still had a good relationship with them both after this.
I now have 3 children though and my Dad has not even bothered to drive over and see DC3 (so it's now over 4 years since I last saw my Dad) and only met DC2 when he was a baby (because I drove over to see him).
It just seems weird that my Dad who I lived with for 20 odd years now doesn't bother to contact me, does anyone else have this situation ? Is it because I am an adult ?!
After he last saw DC2 I used to text and suggest they come here for dinner (he would then say "yeah we will sort something/Stepmum is working, child busy with school etc), Stepmum is lovely so she's not the reason he doesn't contact me. Then I just decided a couple of years ago to stop chasing for a meet up and see how long it would be before he contacted me (partly knowing he wouldn't).
So here we are years later and he has not contacted me, we live about 2 hour round trip from each other. He works and is perfectly fit and able etc.
DH can't understand why I don't contact Dad more, but honestly what's the bloody point ?! Surely you would expect a fit able Dad to drive and see his newest Grandchild too?