It starts with Malfoid and ends with nobody keeping any sort of count, and at some point the fire is only embers.

Mione is the one who says the thing out loud, which nobody expected, least of all her.

MioneI want to watch. And then I want to not just watch.

Malfoid does not sneer at that. She moves over instead, and makes room, and the room stops being cold.

You end up on the rug with both of them and no plan at all, and somebody's hair in your mouth for most of it.

When it is over nobody gets dressed and nobody leaves.