Hmmmmm . . . draw a pink line down the middle of the room? That should keep him on his side. Move all the storage to his side and set up your space, "girly style". If that doesn't work, build a wall to separate his area from yours. The wall can be cabinets or shelves. Is this too drastic? I don't think so. We all need our space. He should be able to understand that, right?