DH and I used to get in tug of wars over my pillow. We'd both be sleeping and all of a sudden, a pillow would get yanked out from my under my head and my head would land on the mattress. I'd wake up (annoyed) and grab it back. We'd both tug on it until I said "LET GO". He'd wake up, see my pillow in both of our hands, say sorry and we'd both go back to sleep. It used to happen all the time.
Two, one really large long pillow and one normal sized people.
Granted, when a certain someone is in the mood for it (And is taking a break from sleeping on my head, back or chest) one of them becomes annexed lol and there goes my head either on the remaining pillow or just laying on the bed without anything.