I love the jokes surrounding Bruce Wayne forgetting his kids aren’t biologically related to him. BUT I also like the idea of Bruce forgetting Damian is.
Like how he health screens all of his kids frequently, in which he asks questions he already knows the answers to, for documentation purposes. Sometimes the kids needed extra screenings, based on what’s known about their parents or their parent’s health. I’m imagining Damian doing a double take when Bruce first begins to ask the same type of questions that he asks Dick, Tim or Steph. “I don’t know, father, what is the status of my paternal grandparents?”
Bruce is going through paperwork and notices he has the same blood type as Damian. Out loud he mutters “how funny,” before realizing that, no, that just makes a bit of sense.
Damian asks Bruce why their eyebrows are so thick and he laughs, assuming “why would I know that, kids are so odd,” before remembering the Wayne eyebrows are genetic. It’s his fault.