Can you claim a kitchen cupboard before you’ve even moved in?

So all of us who are moving in are mates and before one of us has properly moved in (getting his key, bringing anything into the flat) he’s claimed a kitchen cupboard by putting a hat in. Now I’ve moved in, got my keys day after and he’s still not moved in. I feel like that’s fair game to take that cupboard as he’s not officially moved in and he’s just taking the spot before anyone else to make sure he gets best stuff before anyone else can and that’s why he showed up.