My wife sleeps on one side with about a million pillows, and the cat sleeps in the middle. Over the course of the night, she slowly seeps further and further into my side, and if I get up to pee or anything she is in my spot when I get back. This is my life now.
I have had very very small bedrooms where the bed take >80% of the space. It's really hard to change the sheets and such. :( but cozy once its set up.