Can first strike map pack be used on 2 different ps3s?

me and my brother both have the game and ps3s and i dont want to pay 30euro jus so we can both play the new zombies map. If 1 of us pays can we both use it an play online together at the same time?? im not trying to do anything illegal i just dont see why we should have to pay 30euro for 1 map when we live in the same house and dont even want the multiplayer maps

Yes. You can download content on up to 5 different consoles. Obviously they don't want you to, but you can do it.

Yes, it can.