Dear Queenie,
We love to entertain our friends in our home, but there is one couple that never wants to go home. Even after all the others have left they stay and stay until all hours of the night even though they know we have to get up early the next day.
Queenie, is there a polite way to tell them to go home?—Lingering Etty Ket
Dear Etty Ket,
It would help if, when you invite your guests, you make it plain how long the visit will be and about what time it will end, and doing so is not rude. If you have clearly set a time limit on the visit and a guest(s) stay past that limit, they are the rude one(s) and I see no reason to be especially polite to them. Feel free to tell them the visit is over and ask them to leave.
And you might want to consider limiting your socialising with such a person(s) to venues outside your home that close fairly early and/or where you can leave whenever you are ready, letting them stay on if they want to.