Should I acknowledge the younger one?

Question about video calls with kids after reconnecting

So my eldest (16) reached out three months ago after 6 years of nothing. we’ve been doing video calls twice a week which feels like a miracle honestly. But here’s my question - his younger brother (13) sometimes appears in the background or makes comments, and I can tell he’s curious but also… conflicted?

Last week during our call the younger one actually waved at me from across the room but then quickly looked away when my ex called him over. It’s like he wants to connect but is scared.

I don’t want to push anything and risk losing the progress with my eldest. But God, seeing that little wave just broke my heart wide open again. He was 7 when this all started.

Has anyone dealt with this? When one child reconnects but the other is still… stuck? Do I ask my eldest about it or just wait? The Raad said to let the children set the pace but this feels impossible to navigate.

I’m so grateful for what I have but also terrified of messing it up.