I take it you don't date much? So if she was making an effort to dress sexy all the time during month one, but by month six it was sweats and period panties around the house, she was being fraudulent as well? That's just the way relationships work bro, particularly after you get comfortable with each other.
Just because I was willing to sacrifice a Saturday playing Top Golf with her and her annoying friends, doesn't mean I'm always going to be open to doing that. A lot of Saturdays I'm going to want to spend the day playing Dragon Age instead, and that doesn't mean I don't care about her, and it certainly doesn't mean I'm cheating with the 22 year old marketing chick that my GF spotted at the Christmas party and was convinced that she "was looking at me". Get it?