How do i play battlefield 3 multiplayer on two diffrent consoles?

Ok, i bought battlefield 3 yesterday and I have two xboxs. I have an xbox in my room and one in my den and I want to play the one in the den because it's a bigger tv but I already activated the online pass on the one in my room. Is there a way I can play multiplayer in my den? If so, please tell me it would help a lot. thanks!|||lol just put the xbox with the activated online in the den.. online pass = 1 use only|||simple all you have to do is take out your hardrive and put it in the other xbox :)|||hahaha. DICE wants your money. Either move your Xbox into the den, find an online pass, or buy another copy.|||Okay, you can only play on one console on multiplayer UNLESS you play on your account on another console. Stores however do sell online passes to people who are buying it second hand etc so you could buy one from there.