It will not help you get it, but it could hurt you. You should just play the W/L game. Just have the confidience knowing that in your situation you can wait it out until the bitter end and can come on a moments notice. That should give you an advantage over many W/L's.
Agree with cnc2.
You could say "I'm waiting for the GSB decision before I take mine, since this is my dream school blah blah" and sound really cheesy and/or desperate.
Or you could coolly enquire and play on with the game. I'd go with this. Play a poker game. Show them you're still interested. But don't let them think that your interest is your weakness.