Every few months or so, Dick makes a big deal about "finding out he's adopted."
He'll just burst into the Manor, or Bruce's study a call from Bruce saying he has something urgent to talk about and how could Bruce not tell him this and Bruce comes running and Dick's just like "I'm adopted?" Acting completely serious and Bruce is just like "Wtf? Are you concussed or on something like?" And Dick's just crying dramatically like "All this time, you weren't even my true father, how could you?"
As a bonus: Jason bursts in right after and is like "Who let him find out? How could you Bruce- wait a ssec, am I adopted too?" And he turns to a 'sobbing' Dick and starts crying too as Tim nods solemnly and Bruce just stares at his sons for a solid two seconds before just walking right out because he can't deal with this shit, not today.