I'd say yeah, he is probably being entertained by someone for sure. My DD was the same, for quite a few years too. She would tell us about the man in the corner of her room, then one day at my parents she saw a pic of my mums dad who passed away when my mum was a teenager. We had never pointed out who he was, until this particular day when mum showed her the photo and she said she knew who it was, it was her poppy! My mum just about fainted lol.

I get that feeling with DS too, that someone is standing off to the side of me talking to him, and especially when I am putting him down for the night, I get the feeling that someone is standing nearby...