Even beyond the connection they have through their dreams, Hannibal finds Will endlessly fascinating. He has a delightfully dry sense of humour, and though their first meeting was purely professional, he's enjoyed their conversations since then.
And really, Hannibal has so few real friends as it is. Why shouldn't he want to spend time with someone he gets on so well with?
"Will," he says, as he ushers the man inside. "You look well this evening. And you've brought a bottle of wine, how gentlemanly of you. Please come in. Dinner will be ready shortly."