Did any of you have one of those old-style lofts with wooden slats being the only safe things to stand on and a kind of fluffy material in between them, which looked like dirty candy floss? You weren't allowed to stand on that stuff as you'd fall through the plaster of the ceiling below. Or so I was told. I saw it happen to Sweep (and Matthew) on The Sooty Show once as well, so clearly it can happen.
So. Do you have this material in your mind? Now picture an entire room made of it. You can walk in it, but you sink down to your knees and it's difficult to move anywhere. The walls, made of the same substance, have little alcoves in, in which cats like to hide. They're confused by the floor, like they often are with snow. Imagine you're trying to tempt them out, but since you walk very slowly, you're not doing too well at getting over to them.
Still with me so far? Good.
Okay, now imagine about two or three random naked couples having sex in various parts of the room, and you'll get the dream I had yesterday evening.