The way I look at this is that you don't truly love your girlfriend. Maybe it's a subconscious thought, but you don't want to be with her. You keep dumping her, you think of other women, and you even introduce her to your crush? Rewind, you have a crush when you have a girlfriend? That's a problem.
I'm sure you don't want to hurt your present girlfriend's feelings, and so you've stuck with her. But if you truly loved her, you wouldn't think about other women. Why are you with her? Truly? You have to ask yourself that.
Honestly, your ass would've been out the door years ago if I was in her shoes. I don't lust after other men when I'm in love. EVER. I don't think about my ex-boyfriends and how they're doing. I don't care. I don't crush on other men. I love, adore the person I'm with and I care only for him, and he cares only for me. The moment he starts thinking of other women, it's out the door. If you truly love a person, you don't think about being with others.
Go to Heaven for the climate, Hell for the company.