What should i do? should i feed in to things, or just let them be?

im not getting the whole pic! i dont understand y anyone would want to make someone jealous or try and get them to turn there head twards you when they clame that they dont want anything to do with you! i have a ex that is always trying to strike up pointless convo and calling me privet and wondering what is going on in my life and with who, she goes out of her way to find things out about me from others cause she dont have the nerve to ask me cause i might think for a second that she still cares! if you dont care about someone or invy them what is the point in going out of your way to try and destroy the relationship you are in and go out of there way to contact your partner to try and destroy what you have going on, so that they just might brake up with you and will be back on the market for her? i know for a fact that she is not with anyone right now and it seems that making conversation with me agin is okay, shes wanting to bother me hoping that the feeling will resurface???