She KNOWS you love her. Get serious, she's leaving you and is still confident of getting that response from you. She KNOWS. Or she would not be able to play you as effectively as she is. She is still leaving, right?
None of us is advocating being an a-hole. If she says I love you, think of a response that is kind but not always ILY back. Something light, like "ditto" or "well, shows you have good taste". Gauge the moment. Sometimes say ILY back. NEVER initiate it - not in words or texts.
I can only speak from my own experience. I have done this dance. In my case, the ILY were not anything but a way to assuage his guilt about screwing around. To us, those words are true and sincere. To them, they are not always. They may be true, but there is also a whole subtext behind them.
Look to her actions to guide you; words are too easy.
