<human>: So I've been going out with my girlfriend for 8 months, and in a recent argument, my girlfriend revealed that she wasn't happy with the way I "look other girls up and down" and that it was "pretty obvious", and that sometimes when I'm doing it, it seems like I ignore her.

Now this really affected me in a big way.  I was pretty hurt by this accusation that came out of nowhere.  The problem is though, I don't even recall ever doing this in front of her.  It's not even something I do often or at all for that matter.  Occasionally I do zone out though or get caught up in my own train of thought while I'm with her (I mean who doesn't?), and the only explanation I can think of is that maybe I unconsciously do it while I'm not paying attention, because it's not like I purposely stare at other women to check them out all the time or anything.  But I feel like even this is simply just myself justifying what my girlfriend said because I feel horrible about it.  It might not even be true. 

I've ended up feeling horrible about myself a lot of the time when I'm out with her, and I tried go out of my way to try and not look at other women at all because of this.  Which, if anything, is kind of a stupid solution to it because women are everywhere, so avoiding them would just be avoiding looking at the majority of my surroundings.

Is it fair of her to accuse me of something like this?  Is this even a problem for all you other people in relationship?  And what should I do about it?

Condense the text into a few key points
<bot>: Girlfriend is hurt that I look at other girls and I didn't even realise that I do it.  What do?