Balthazar will keep it all hidden as much as he possibly can. Protecting Castiel is something he still can't help, despite everything between them. Besides, even if no apologies are offered, he can tell he isn't the only one woefully uncomfortable with this situation. That helps make up for it a little.

They hold each others' gaze for far too long to be comfortable, and Balthazar looks away as Cas runs his hand over the back of his neck. "No, no - you stay. I'll go. I need a drink, and what they have at this party isn't nearly strong enough for my tastes."

He pauses, licking his lips as he debates if there's something else he has to say to his old friend. "Castiel," he thinks maybe, he should tell him that they can fix things eventually. It hasn't been that long - he still needs a bit more time to sort through it all. No. He doesn't want to burden Cas with the knowledge that it's only been about a month since his arrival in Medietas, and he arrived directly after his death. So instead he finishes off lamely with, "Gabriel's here, too."