My ex fiancé keeps denying her infidelity. She says she never intended to hurt me so her cancelling our vacation plans to instead spend a long weekend with her affair partner who abruptly, and against her initial wishes, showed up at her door wasn’t really an affair against me. She becomes defensive every time I try to offer her forgiveness. No matter how safely and politely I try to explain my feelings, she becomes defensive, argumentative, and abruptly goes away, only to approach me days or a week later wanting to try reconcile and says I am too obsessed with the past and should just “get over it.”