Thanks everyone.
Sorry - I actually tried to post a longer message, but it would not let me do it, so I just asked the basic question without the full explanation.
We have actually booked two rooms - hopefully one king HA and a connecting double-double for our 2 kids. However, my sister and brother and friends and all of their kids will be there, so the kids will be playing musical beds/rooms all week long. I just wondered if my son could sleep in our room some night when the girls take over the connecting room.
Thanks again!