Fake Freak
feyk freek -noun: a person (frequently, but not only subjected to, females) who presents a persona, belief, or act (physically and/or emotionally) that leads another party(-ies) to a reasonable assumption or belief, then selfishly changes the belief or assumption to the dismay of the aforementioned party(-ies).
ex: After weeks of excessive verbal and physical flirtation, Amy, that fake freak, told Antonio their relationship was only platonic; to the surprise of Antonio who believed the interaction between the two symbolized otherwise.