Even though you already have a copy for your wife, you will still need to purchase another copy to gain access on the PS3. You'll have to create another user account on the PS3, along with another PSN account. Then go to the PSN store and buy another copy (digital). You won't have to install it, but you'll need the codes to use it on this new account.
I think you've been smoking the Moko...
Angus of Cerberus (retired)