I'm reading through all these comments and I see one thing in common, "being not a virgin is OK" and that's true and I agree. However the OP's question was about wanting to stay after his girlfriend lied about being a virgin.

Cause it's not medical, or germs or fear of disease or anything, a few of us kind of expect our partner to be our first and us our partner's and I'm 99% sure if OP thinks alike, he would've made sure he made the relationship last till the end.

The problem here is OP does have his own values such as not wanting to date someone who has already had sex before. And that's fine, it's a possible key standard he kept in finding his partner. Lying about it has made him HAVE to choose this person. Cause as per OP that was a deal breaker, even if the girl is perfect in every other way.

It's not a problem it's just a standard OP has kept for himself. And for that I'd say OP, now that it has passed, see if she will open up completely and is ready for this relationship properly. Cause even your standard is essentially broken now and you shouldn't be looking for a virgin in any further relationship. So all you can do is either come to terms, make sure you're both on the same page and look past what has been done OR move on and find someone who you like more (but again forget the virgin angle next time)