To be honest, Sam doesn't much care what Zachariah thinks. He knows that he's not the other man's first choice for a mate for Castiel. In fact, he's pretty certain he's near the bottom of all potential Alphas in the world. But it doesn't much matter to him because the one who does matter is Castiel.

"A little warning would have been nice, but only so that I would have been here to greet you when you arrived instead of making you wait." He raises his head, looking to Zachariah. "You are, of course, invited to take supper with the pack tonight." Though he doubts that Zachariah will. In fact, he's counting on it. Because there's somebody he'd really like to call to have supper with them instead.