Thank you for posting in our answers forum! That's a great question. If you are connected to the Slingbox, and your wife were to try to connect as well, it would say "another authorized user is viewing your Slingbox, would you like to disconnect them? Only one user can connect to the Slingbox, at a time. Also, If you change the channels from away from home, it will also change the channel on the cable box.
Hope this helps!
The Sling Moderation Team