I let my cats sleep in my bed when they want. It's an adorable idea for me, but I usually don't get much sleep when they do. I don't move around a lot in my sleep, but I'm always afraid I will when they're there. It's worse if they lie on top of me, I feel like I'm in a very comfortable position until one of them climbs on top and then I instantly feel like moving. My older cat used to sleep at my feet every night, and I was always scared that I would push her. She would stretch higher and higher on the bed, and in the morning I would be curled up in the fetal position. Now she likes to sleep over my head, I'm really happy with her choice. My younger cat picks his sleeping place randomly.