Genuine question as I really don't know.
Db is 20 and officially lives with us. He spends 3 nights a week here on average and 4 nights at his girlfriends. He has his own room.
Ds is 8 and shares a room with Dd 5 and dsd 5 who cones 2 nights a week.
Would I be unreasonable to ask Db to share with ds and then Dd and dsd would have a room to share?