I'm a little confused at all the hand-wringing. I've honestly never had friends over for dinner where there wasn't a natural conclusion to the evening. Sometimes evenings that I'd initially planned on us all playing board games over a bottle (or three) of wine ended prematurely due to tiredness or whathaveyou. I've also had evenings that we'd initially planned as a quick supper turn into all-night gab fests. If I've planned a specific after-dinner activity, I will let my guests know, but other than that, I just play it by ear.