At this point, Dave doesn't feel particularly helpful beyond being a meatshield, but he will continue to do that to the best of his ability. Terezi is better at explaining this, she's already figured it out better than he has. He can't help berating himself, but that's all in his head. He's just going to fall silent between them and let Terezi do the talking while he does the separating. If she can get it across to Rose, with him there to prevent her from lashing out, they might be able to handle this without a peacekeeper dragging his girls away by their weaves.

He gives Terezi a little nudge with his elbow to let her know that she can answer that one, that he's just here to support her argument.