"My bed's too small"

So Vance has been sneaking into our bedroom at night after we put him to bed in his room. When we go upstairs to go to sleep he is cuddled up and fast asleep on Dadduy's side of the bed. Yesterday he refused to take a nap and I asked him what was wrong and he told me "Mom, my bed is too small!!" So now we are on a hunt for a new bed for him. In the meantime (until we get the money) we have blown up our air mattress for him. We thought this is perfect it is a queen size and he should love it!! Where do you think we found him last night when we went up to bed? Yup in our bed fast asleep!!! Oh what to do now........