I have trouble sharing a bed in a non sexual manner for the simple reason that inorder to beable to comfortably sleep in a bed with someone I need to beable to cuddle right into them or else i can not comfortably sleep. This is only recently for some reason though. 4 or 5 years ago I could share a bed with a friend or a cousin no problem (unless the kicked or something in their sleep).
When I have kids I do not think I will have them in my bed all of the time. I will definately have them in my room when they are babies but probably not in my bed.