vato said:
"
You have no feelings. You've probably never been hurt
Geez you sound just like my ex-girlfriend !!
Haha but seriously though... i think she actually did say this to me. Anyways, most likely she either got dumped/cheated on after a (what she considers) long term / serious relationship recently before she met you. As weird as it is... you need to make sure that whatever you do with this girl, that she treats you as YOU, and not another guy tryna screw her over.
How to re-frame.... hmm.... I guess it would depend what you're trying to do with this girl... make her your gf / or 1-night stand.
Try
"Yup... well I used to have a heart but it took up too much space so i sold it on Ebay."
or maybe "Well now your just assuming... and you know what happens when you assume."
But me personally... I'd just ignore that statement and steer the conversation in a another direction completely.
Good luck !