First, I wouldn't get relationship advice from HN, or any pool of nerds. There's a reason our relationships suffer or are few and far between: nerd personalities will spend more time coding at work, trying to build a side project, watch TV or play games than being a healthy, balanced human being. I work 40 hours a week. If I have work shit poking into my life beyond that on a regular basis, it's time to talk to my ma…
So if you wanna work all day, find a way around your gf's complaints. If you think your gf is pushing too much then probably she isn't for you.
Sometimes I have the same problem and I try to be very straight: I always worked so much!