Can it even be possible?

What is this feeling I am experiencing? Anger? No. That can't be it. Frustration? Over what? 
Every time she posts something to him on that stupid social network website that is even remotely flirty, I get upset. Am I jealous??? Is that even possible? I'm happy in my relationship. I'm ecstatic to be where I am in my life. Why does it matter? She's single. He's single. They even know each other. What's the big deal, Leila?
I had a crush on him for YEARS when I was in middle school and he was so much older he didn't even know that I existed. Then, he and my oldest brother became friends and I crushed on him even harder. He graduated high school without ever speaking a word in my general direction. 
Adulthood came around and in my stupor one night, he and I became social networking friends. Then began the midnight chats while I worked crazy hours and he suffered from insomnia. We use to talk on a weekly basis about life and offer advice to each other even though we had never really met. The idea of getting together one day was kicked around a time or two but it was never ever acted on. I admitted to him, one night among a playful conversation, that I still harbored a little crush on him and looked forward to talking to him whenever I saw that we were both online at the same time. At that time, he admitted to forming a little bit of a liking to me as well. Boy oh boy did my head soar that day!! Could it be?!?! Could my middle school crush actually be crushing on me now as an adult?!?! For serious???
Then, life changed. I got thrown a curve ball and took off after my heart once Craig swooped in a stole it from me when I wasn't looking. Things have never been the same. 
I think Zane and I have only actually IM-ed a handful of times in the past 4 years. Even less than that, maybe. An occasional comment here and there on each other's status or photo post...yep...that's it. 
So why do I suddenly think horrible thoughts every time this one particular female friend of ours makes a flirty comment or hints at going to visit him? 
I must still have a crush? Is that possible? Is he "the one that got away"?? Can't be. I never had him. Never had a chance with him. I guess he will always just be there.....hanging in the background.......the road not taken.....the adventure never explored. I guess it's better that way. 
Just breathe in and breathe out, Leila. You are fine. You are happy. You are complete. Let it go. Let him go.  Rock on, Haley. Go for it. Hope you two can find happiness. I will just fade into the black background and go on as a spectator. Don't you ever dare hurt him, though. Don't you try and change him either. He's perfect the way he is and doesn't need anyone else's approval. I'm warning you, little lady!! LoL

Thanks for stopping by and don't forget to feed the fish on the way out! :)