PS: I forgot to mention that maybe he finds your presence in his room stimulating. My
DD is a brilliant sleeper but she simply cannot sleep if Daddy or Mummy are in the room with her. She needs to be on her own to go to sleep. It's been quite strange for
DH and I to get used to - that we give her some cuddles, put on her music and leave her to get on with it. (NB: I don't believe in control crying, she does not cry herself to sleep at all, she just plays in her cot for a bit and then gradually winds down. She wears a sleeping bag for all her sleeps so kicking off the covers is not an issue).
DS used to scream blue murder if we tried doing this and even now one of us still has to lie down with him while he goes to sleep at night - he needs the security of our presence.
Sometimes
DD might need us to pop back in to pat her bum for a minute or so if she's a bit overtired and having trouble drifting off completely but we have to be careful to time it right because as soon as she sees us we get big smiles again.