I have been on the recieving end of this EXACT SAME SITUATION. Thankfully, it has had a good ending.

We used parental controls for a while. But what PC are good for is a TEMPORARY measure to help you learn your own self control. Like with most addictions, the only real changes will come from inside, and as many recovered addicts will confirm, the easiest way to do that is to avoid the addiction - even the temptation - altogether. Your Girlfriend cannot and should not have to act in place of your mother or watchdog. She has the right to say no, she doesn't even want to try.

Honestly, it was very very very hard to trust the Significant Other when he said that things were changed, that important life responsibilities wouldn't be neglected. He said that before (and meant it too! right up until something really important was ignored), but it is a burden of trust that, if there is even one slipup there's real and serious consequences not just to you but to the significant other too. You miss WoW, and that's real. You miss playing WoW with your girlfriend, and that's real too. But it sounds like its safer to pick something else, something short, something with a definite end, something that you can't easily go off and solo play without her, if that makes sense.

Don't jeopardize the good thing you've got going. Even my "happy ending" was full of a crap load of heartbreak, frustration, and anguish along the way. Sometimes makes me wonder if it was worth it.