M.P.
He's old enough to be crying it out, if you have the patience. His personality might not accept it, though. My girls go to bed in their own rooms, but if they get up in the middle of the night, they come get in bed with me. I kinda like that they do this- they won't do it forever, and it makes for some nice morning snuggle sessions. As long as they START the night in their bed, I don't care where they finish it. They won't be little forever.