Ladies, what is my ex really thinking because I would really like to know.?

My now 48 year old ex-girlfriend left me to go back to her 60 year old ex or I guess now current boyfriend for a third time, after I had a falling out with her 26 year old daughter that was staying with us in my house, and I wanted her to leave. They all, including the 8 year old grandson went to stay with him. The daughter wasn't always following the rules, and she brought too much drama. Then the day after I had the run in with the daughter, I discovered my now ex-girlfriend had been messaging the 60 year old ex, telling him about our business, asking if the rooms were ready yet, telling each other how they missed each other and how they love each other. When I busted her about it, she downplayed it saying she was just telling him that to get what she wanted and that is to have her daughter and grandson have a place to stay. The day after I busted her, she texted me saying she fell out of love with me because I didn't make her feel loved. How that is, I don't know, I told her everyday, and I would show her from time to time by thanking her for all she does and hugging her. Maybe I could have done more, but by no means did I neglect her. I think she said this because she didn't want to be accountable for her communication with her ex. Now the daughter is getting her own apartment, but my ex is staying with her 60 year old ex/current boyfriend. Why can't she come back and work it out with me? We seemed to be doing just fine til 5 months ago when her daughter moved in.