Timorous

There is a way to get this to work with steam although it would obviously be better if Obsidian made an extra copy available to avoid doing this. If you log into steam with your account on your SO's computer and install the game then set steam to offline mode it should work fine on both computers. This is obviously not an ideal solution at all but it will work in the interim until you either get your physical copy or Obsidian make another key available to you.