When we had our parties and/or if people are driving a distance to see us and knew they'd be drinking, we always offer the option of sleeping over. At the end of the night though we are all "sleeping" with our own partners.
One time I wound up in the miiddle of a king bed with my wife and another couple that slept over and it's just a PITA when you need to get up to hit the bathroom. Nobody gets much sleep and it's usually a very late night anyway, so every bit of sleep helps. If people are up for morning sex we can always get together then.

