I want my Ex-bf back, what do I do?

Scenario/Question: My ex-bf have been broken up for six years now. In that time, I have been married, and now recently divorced. My ex-bf is has also dated plenty, and is now in a relationship that I think may be somewhat serious. While I was married, he constantly admitted his feelings about me, and even tried to convince me to leave my husband to come be with him. Although, I did love him, and it was tempting to leave, I didn't because I still married and told him it wouldn't be right to do so.

My ex-bf were together for two years, and friends before we started dating, and we are still friends, even now. I'm still friends with his sister, and even have trip scheduled to go visit her soon. My ex-bf and I broke up over a pregnancy scare that neither of us were able to handle. I felt that he dumped the responsibility on me to terminate the pregnancy, and felt abandoned by him. I felt that he put medicine over me, as a priority, and didn't consider how hard it was for me. It was all too much for me at the time so, I ended the relationship.

He has a new girlfriend, and seems to be into her. It's really unfortunate because I still love him, and honestly I feel like he is the only man I can truly love. I miss him and I want him back, now that I'm officially able to do so.

We text back and forth regularly, although the messages, are pretty brief. I also find that recently, I am the one initiating communication.

What do I do? How do I go about it? Do, I make my feelings known or just let things be ( which is what I'm tempted to do).