He eyed Margaery for a moment or two, then looked back to Thomas. "How about you explain and then I'll decide if I'm going to sit down and share food?"

He's not trying to be an asshole but wolf and snake weren't a great mix, even if he recognized that the snake wasn't harmful to him. Some deep seated caution, and then layer in the fact that it talked to him, and, actually, where he grew up.