Which is interesting, and probably due to the fact that nerd girls have a reduced defense system. First of all they are probably not used to the idea of being attractive to someone, which means they are not prepared (YOU ARE NOT PREPARED! (or, you know what I mean). And secondly, they are probably so busy gaming they rarely even realize that they have entered a relationship.
And this is quite normal, just think about it. It makes sense. How many remotely sane gaming girls do you know that is single? (Well, I could actually think of a few right now, but all of these chicks are either stationed somewhere in the farthers corners of uncivilized Snoreway, or in fact too fast). Which is a gift. If you are able to run away soon enough - you'll be alright. Or, you could always just move to somewhere safe. Like the moon, or Yemen, or somewhere you have to wear either a full-bodysuit or -grow a beard, which could be either of the two places.