Loved the back-and-forth, and the couple of bits of something deeper.
"So, you and my mum, huh?"
"This trip down memory lane is now at an end. You may pick up the cheque for my drink."
That was nicely sharp, in the midst of the comfortable antagonism they had going. Makes me think they've got some unpleasant conversations ahead of them, after they get through the initial tear-the-clothes-off stage.