Am I in love with my ex after 14 years and 3 marriages?

This is a long story:

I met my ex when I was a senior in high school. He was my first everything. We got engaged and moved in together. I broke it off because I thought he was too clingy and did not hold down a job and I didn't want to end up on welfare like my family.

I quickly jumped into another relationship (husband one), got pregnant and married within 3 months, and divorced in less than three years.

I married husband number two about a year and a half after the divorce of number one. I met him at a bar. I married him for security reasons while he was being deployed to Iraq. He ended up being abusive and angry. Two kids later and 5 years of my life, we divorced.

Husband number three was met online. He was nice and considerate with a stable home and good job. He treats me really good and I know I am safe and secure with him. I thought he was the one for a while. But now I think I might have just settled for security and comfort and not love. We have been together for three years now.

Throughout all these 14 years since the first guy (high school ex), I have thought about him often. I have wished I could go back in time and change my mind. I have looked for him everywhere I knew he used to hang out. I have tried to get my mom to call his mom and ask about him. I could never find him. I have always felt like I love him though.

Randomly skimming friends on Facebook a month ago and his profile popped up. My heart stopped. I added him as a friend and held my breath. Within hours he responded asking about my life and telling me about his. Asking about my family. Then he asked me for my number which I gave. I told him i'm married and that I would only talk to him if my husband approved. I told my husband I talked to him and he was iffy but didn't say I couldn't talk to him. So, he stopped by where I worked to see me and we were both kind of shy and nervous. He gave me an awkward hug and told me how good I look. We have been texting and talking since. I have all these old feelings for him and he feels the same. He said when he told me he would love me forever when I was 18, he meant it.

The thing is, I feel like he is the reason none of my other relationships and marriages have worked out. I feel like I've always loved him and have just been waiting for him. I have settled in relationships I was unhappy in, just to be in relationships. Every bone in my body wants to run away with him and never look back.

But, my husband is kind. I could never hurt him. I can't cheat on him. I can't bring myself to leave him.

But, me heart aches for the other man.

He has been in a relationship with a woman who cheated on him for 2 and 1/2 years of the 12 they have been together. They have two kids but have never married. He has never been able to marry anyone since I broke off our engagement. He still loves me. But, he also doesn't want to leave his kids. Even though they are older kids (pre-teen), their mom has threatened to take them if he leaves her and not let him see them.

I don't know what to do.

It's not fair to my husband that I think about this other guy all day. I don't want to hurt him. I know my heart is selfish. I know I shouldn't want another man while I'm married. But, he is all I have ever wanted since I left him 14 years ago.

Please advise.