"Are you friends are you in love with the girl?" The Doctor made a gesture towards her, "You talk about her as if she's the love of your life after all."
Taking a sip from the glass he watched her then made a mental note of her name. For a few reasons. He supposed Willow was right, if the girl didn't want to be found she wouldn't have reached out, which made The Doctor all but a little suspicious that the two of them might attempt to escape together. But he knew he could find them again, but he really wanted to use this as a test. See if Willow really would come back, because if she did? Then it told him he had the green light to move forward, because she at least enjoyed his company enough to come back.
The thank you was a bit unexpected and at the same time very appreciated. Smirking he shrugged, "It's nothing. As for the special, yes you'll like it. Surprisingly enough, there's nothing sexual about it... but I'm not going to tell you. If you're that curious, you should come back to find out."