Be careful of forming an emotional attachment, or a jealous attachment. It is unlikely that you'll be comfortable in a 'stable' relationship with her, considering that you've previously observed her behaviour in previous relationships.
This is a similar reason why it's never a good idea to steal a girl from someone, because then you have trouble trusting the girl in the future.
This is a similar reason why it's never a good idea to steal a girl from someone, because then you have trouble trusting the girl in the future.