nice people get walked on
kind people are respected
if she cant understand that youre serious about what youre saying then play the guilt thing on her. you thought she was a good person but shes trying to ruin your relationship for a little fun. and i mean youre making excuses for her actions and you sound like youre interested in her.
if you are then cool, if youre not then thats cool too. but just know that you have to decide and not joke around with it. if thats the case, then youre not really serious about your relationship with your girlfriend and it wouldnt make any sense to worry about screwing the new girl since youre not that serious...if thats the case.
if youre serious youd just ignore her provocations and just stick to light conversation or avoid speaking to her when she tries to bring up sex. and if she doesnt understand get one of your friends to be a wing man when she comes to town and you can try and put them together to get her off of your back.