The hot tub loses a lot of water when you get eight people into it. It's also a lot of fun.
The first interactions that seem to occur between social circles is singles hooking up. In the absence of the sex/dating motive, the groups stay relatively separate most of the time. On the other hand, singles seem to mix between groups much more freely. I'm including available poly people as "singles", at least if their dance card isn't currently full.
Saturday parties let me do more bustling around and preparing -- more time to cook more food (that's why there were three different kinds of chicken, plus portobello mushrooms cooked in wine), more time to clean up, etc. So I have a bit less fun as a host, and I'm far more exhausted at the end, but the party comes out better. With more food prep in advance and more disposable silverware, I might have had to do less, both during and after.
And apparently the hot tub was turned up to maximum temperature in the drizzly rain outside, which explains why it's been so audible. I turned it way down. But if I grab a towel quick I can go soak in it before it cools off. After a strenuous weekend like this one, I choose to interpret that as a sign, even though it's already around midnight.