Merry Freaking Xmas

It hurts me to even talk about this but I figure perhaps it can be therapy.
The boyfriend was excited about me going back for my holidays (3 weeks). After 3 days he decided that he needed to dump me and leave me completely in the lurch with many things. No place to consistently stay, no vehicle to drive around now, no way to eat etc. I would spend 2 nights at one friend's house, then 3 nights at another, then 2 nights back at the other's. It was awful in it's entirety. I had to get my one friend to drive my ass around and clean and babysit so I did nto feel like a burden to them. Ugh. I hate men.
So I suppose my major complaint is: Why is it that people in relationships don't understand that an emotional affair is still cheating?
The now ex-BF was having a continuous conversation with 2 girls that was wholely inappropriate for a guy in a relationship. And one of the girls was in one also. (Yes, I did something very very wrong here too. I am aware of this. I read his personal conversations without his permission. In my defense, if it is even possible to have one, is that I knew something was up and no matter how much i tried to discuss it with him, he would slough me off. I have ben cheated on by every single guy i have ever seriously dated, so I am paranoid).
When I am with a guy, I respect all that entails. I do not flirt with others, do not carry on inappropraite conversations, and i certainly am not physically involved with anyone else. Obviously if i like the person enough to be with them, I should respect that.
So why is it that I seem to be the only person who has this idea? He claimed to like me and yet would sit there and tell her how wonderful she is and how her BF doesn't appreciate her and how she can do so much better. (Implying of course that HE is the one that could assist her with this quest for utopia).
When I confronted him after about it I asked: "So the point of that? Is the the thrill of the chase? The fact that she might dump her BF of x years for you? The fact that if she does that somehow validates you as a person and fixes your screwed self-esteem?" He had no reply to that. I then mentioned that obviously if she did leave her BF for him, that he would always be wondering if she will do the same to him. With good reason. One who is in the habit of searching for greener grass will always be searching.