The first couple of years in my M was unhappy b/c I was so young and had all these ideas about what M life was all about. I thought it would be sunshine & roses all the time. I believe I handled most things fairly well except for the "boredom" of the R. I craved emotional intimacy and my young H craved the physical (which is normal) but he did not know how to fill my needs.
My H wasn't interested in going anywhere. I would try & try to get him to go visit friends or for us to this or that, but all he wanted to do was come home, eat dinner, watch TV, and then go to bed and have sex. That was great for him, but it was slowly draining the life out of me. He was a good person, but I craved romance b/c I was still very young and felt that after the wedding vows were spoken....the romance stopped.
A lot of young men pursue the female by romancing her and then after he "catches" her, he stops b/c he feels he won what he was after (the girl). But she still has those images of soft candle lights, romantic music, and love words whispered. If her H doesn't provide that for her, then she will begin to try to fulill that by either watching movies or reading novels.......or getting into Internet chat rooms, or a co-worker at work, and other places she shouldn't be. In other words, it may start out non-threatening but it continues until she is off into a place that she feels through with her H b/c he's not giving her what she needs emotionally.
So, I just said all of that as a background, FWITW. She's trying to have a new romance in her life. It doesn't mean she loves him, but she has probably tried to convince herself that she does.....and her emotions may confuse the romantic feelings with "love" for a while.
This is the bottom line advice I would give you but most men can't accept it b/c they want to take some other route of action. You can't control what she does.....plain & simple. You can set boundaries, etc. but if she is living with you, then it makes things harder. You need to let her go. Drop the rope. Focus on you. If you will take all your attention off of her and put your energy into becoming a better man then that is the best action you could take. I can almost see you blocking this out as you read it, but I'm telling you that she will have to go through her own stuff and experience consequences to her own actions. She will have to find out what is really in her heart......and you cannot be trying to "tell" her what's in her heart....she has to figure that out on her own.
Men are so afraid to use this principle b/c they say is seems opposite of what they should be doing. It is the opposite of what they should have done during the R....but now that has past and this "is" the action to take at this point. If you pursue her, she will close her heart up until you will never have any chance of getting closer. Telling her you love her is pursuing. Contacting her is pursuing. But if you back off and let her go, and you learn to live life as if she will never be a part of it again......you will become an attractive man. I can't explain "why" except it is just a law of nature. This is something you will have to trust, b/c it won't make logical sense to you.....you just have to do it.
It is not about what you feel should work in your M. It is about doing the work that gets the right results. Do what works!