two things lept to mind when i heard this dream:

1) sleep paralysis. it's considered a sleep disorder, although most of us experience it in one way or another at some point in our lives, since it's natural for our bodies to shut down physically at night in order to re-route energy to the brain for "re-formatting" during REM. you can find out more about it on wikipedia.

if you "suffer" from sleep paralysis (please keep in mind i'm not a licensed practitioner or anything) then it seems to be a mild form of it, in that you don't suffer intense hallucinations and  it doesn't freak you out TOO much. i go through the same thing every couple of weeks or so, but the presence in my bed is usually some friend or relative. i guess it's different for everybody.

2) the little boy. seems to me like you've got some mischievous little spirit guide of some sort. more people on the forum can give you more info on what that means, all i understand is that there are spirit guides that guide is in waking (and especially) in dream life, and it seems that this little boy is it for you. he's yours in the sense that he is here to guide you, and belongs specifically to you. when you find yourself in this state, feel free to try to establish a relationship with the guide, and see where he takes you. when my friends "visit" me, they usually stay at my bedside and help me go through the dreams i'm dreaming that night. maybe yours will do the same?

also the fact that he's so young either says something about your own playful, young nature, or maybe is suggesting that you're just starting out on a wonderful spiritual journey. children are naturally playful, curious, and primed to learn and grow, which is, i think, the state you're in right now -- if that makes any sense....

hopefully someone else with more insight into spirit guides (or this dream in general) can give you more help. check out the other sections of the forum to see what other info you can find. all in all i think of this dream as a really good "omen".

hope this helps!