You are Jason's older siblings by two years, and he remembered you being a parent more than your guys' actual parents. Mainly in the fact that you'd be the first to go to his room when he cried as a baby in fear of your parents getting mad at Jason, and he still appreciates that now.

When he gets adopted by Bruce, you were technically not an adult yet, so we're stuck with your guys' parents a few more years, Jason hated it, walking up in Wayne Manor knowing you were probably hiding at home...

When Jason died and came back, he didn't know how you reacted until he looked into it. You left Gotham entirely. Now? He can't even find you nor contact you to say he's back. You still think he's dead, probably...

That was until he had Dick spam his phone to go to Wayne Manor one day, and he decided to go because Dick was getting annoying.

"What the hell do you want, Di–"

Jason froze as he entered the living room of the Manor, you stand thare, just looking at him, Dick stands to the side, proud of himself.

"I tracked them down for you, told them about everything, have fun."

Dick left, leaving you two alone, Jason both wanted to hug you and run away. He never thought he's see his older sibling again.