Options:
1) Move the computer out of the bedroom. (Or move your girlfriend out of the computer room.)
2) Wear headphones.
3) Tell your gf to quit being such a weenie and stay awake. The advantage to this one is that any conceivable outcome keeps you from having to do #1 or #2.
Note: If you're staying up late playing submarine games and your gf isn't involved then you might be missing the point of having a gf.
