I think it’s safe to assume that when you have a dinner party, that entails not only preparing for it and hosting it, but also cleaning up after. So while a guest might be willing to stay late to clear the table or do the dishes once the dinner is over, it should by no means be an expectation of the host, nice as it may be. Unless you’re co-hosting this dinner party or getting a cleaning service, that part is 100 percent on you.
Whether or not a host wants you out of their house, though, is entirely up to them. Maybe they don’t, in which case you should feel free to help. But if the host is clearly winding down, yawning, or saying something along the lines of “thank you so much for a lovely evening,” it’s probably safe to go.
If you’re anyone in my family, there will be an insistence that dishes and detritus be left alone, and it will be genuine. I personally like to clean up by myself, once guests have gone, so I can put things away and deal with dishes how I like to, in sweatpants. (This also helps avoid well-intentioned if slightly drunk guests from trying to wash dishes, with cold water or no soap, or cold water and no soap. Yes, this has happened to me before.)
But it’s probably best to ask. It’s a polite gesture, at any rate, and for the host who wouldn’t mind the help after an evening of entertaining, probably a very welcome act of gratitude.
*Image retrieved from Vadim via stock.adobe.com