Our three year old has recently started waking up at 3:30-4am every day, terrified (I think sometimes he's actually had a nightmare and other times he just does it out of habit) and wanting to either sleep in our bed with us or have one of us sleep in his bed with him.

His older brother has never had this problem, and we've never allowed them to sleep with us.

He shares a room with his brother so we can't just let him cry it out or he wakes him up. Also, he is old enough to open the bedroom door and come into our room if we don't go in to him (and is not afraid to repeat this process unless his demands are met). We've tried getting him back to sleep and then putting him back in his bed but when he wakes up a few minutes later the process repeats itself.

Anyone ever deal with this and, if so, how did you get your kid to stay in bed?