Balthazar's default setting is upbeat and friendly (if chock-full of denial); even with the Winchesters, who effectively threatened to burn him to death the first time they met, he starts off with a cheerful hello and leads from there into lightly sarcastic banter. Deeply gregarious by nature, he's found it easy to pack-bond with the other angels and not much trickier to do so with the humans around him. For all that, though, he is an immortal celestial being, and there's a lot he doesn't show.

He's basically everyone's drunken uncle or brother--until he's not, at which point he's just this side of an eldritch horror.

"Adventurous," he repeats, and grins. "Well, let me get through this glass of champagne and then we'll see, shall we?" Humans are devious. He's going to draw this out a bit and see where it goes.

"Balthazar," he responds to the unneeded introduction, clasping the man's hand and shaking it with just about as much pressure as is comfortable for a mortal person. "Formerly Ba'al-sarra-usur, but that's a mouthful and I don't regret anglicizing it."

"Now, then, at what point should I give you the glare of death and ask if your attentions toward my sort-of-step-daughter are honorable?" His eyes crinkle at the corners when he smiles, but it's a little hard to tell how serious this question is.