I did lots of thinking about all of this last night. I read and re-read this thread and I came to a conclusion. This is not at all about DH, this is about me.
DH is a wonderful guy and has never given me any reason to doubt him. When I told him I was uncomfortable with his FB situation, he took care of it and de-friended them. I admit, he did not understand why I was so upset about it because I was friends with an ex and that never bothered him. I also think there was a little part of him that was offended (although he did not say it) thinking that I did not trust him. That was not the case at all, I do trust him but to him, I think he saw this whole thing as that I did not.
Why I say this is about me is because well, it's true. I have never had the best self-esteem and that is my problem. I have always been a jealous type person even if there was no reason to be jealous. Honestly. So this is something that I will talk to him about, but I also really need to work on myself. I know I am a good wife and I know that my DH loves me dearly and would never do anything to hurt me. I just need to chill out a bit and realize that and stop being so threatened by it. There is nothing to feel threatened about. It will take a lot of work, I know that. But I wanted to thank everyone for their advice.
I know there are some that will think my DH is up to no good but I can assure you, he is not and I trust him 100%. It is other women I don't trust. Strange because I am one of them, but maybe not so strange because I know how women think and how they work.

So what if a women finds DH attractive. I need to have the mindset of 'I am the one going home with him' and stop getting threatned by it.