So, okay. Jason wasn't exactly thrilled when Bruce went and adopted the Joker's kid. Can anyone blame him? Of all the reminders he doesn't want to have living in his house, anything to do with the Clown is gonna top the list.
And, yeah. He's not been the nicest about it. It's an adjustment, okay? He's not always been the greatest at welcoming new siblings anyway, and it's been a struggle to see this new kid as a 'sibling', to put it mildly. They're here, and apparently they're not going anywhere, and Jason's trying to accept that, but that doesn't mean he's happy about it. And it's showed.
Mostly, he's tried to avoid or ignore them. When that hasn't worked... yeah, there've been a couple fights. Nothing physical, of course - Bruce'd flip - but Jason's definitely shouted maybe more than the new kid deserves, if he's honest.
Look, he... knows this is a 'him' problem. He does. Kid's not picking fights, usually. Jason's the one looking for an outlet. He's got trauma around the Joker - to say the least - and he's taking it out on the Clown's kid. He gets that. Proud? No. But he goes back to, 'can anyone blame him'? Joker's a monster. Jason literally got murdered. He thinks that's decent excuse for a few lingering issues.
So, suffice to say he wasn't looking for company when he got home from a late-night patrol and headed for the kitchen for a snack - and especially not this company. The very person he usually wants to avoid. Great.
Except... the kid's looking edgy. Scared, even. Yeah, Jason recognizes that post-bad-nightmare look. And, well, this is the first time he's ever seen 'em out in night clothes, and he's finding himself surprised at what he's seeing.
He could intuit, he supposed, that growing up with a monster like the Joker wouldn't be easy. But he'd never really thought about it. And he's a bit stunned - seeing all those scars. He's sure thinking about it now. And kinda feels like a jerk. He's not trying to be weird, staring from the doorway. He's just a little stunned is all.