wow for one..to be truly with someone you must be physically attracted to them as well as emotionally and mentally.. but if you don't think she is good looking then you shouldn't be with her because she should be the only one you look at and you should not lie 2 her..maybe you should re-evaluate Ur feelings for her.. everyone is good looking in someone's eyes..but looks should not be number 1 on a person's list..something made you start dating her.. if she is a good person then she doesn't deserve you if you want my honest opinion..u should like her for her and you should care about her feelings and you don't seem like you do..
Well, there's obviously something you like about her, right? Aim for the truth, but not directly. If you must say it, DO NOT say it like in the example. Put it lightly, and make sure she knows you do have feelings for her. "It doesn't matter how you look, all that matters is I love you" <- that type of thing (basically, mix avoiding the truth and telling the truth)