It sounds as though while the two of you have gone your separate ways, there is something missing from both of your lives that causes both of you to want to reconnect. It's not just you! He's missing and loving you too. There are many subtle levels that all living souls can communicate to each other. How many times have you thought of someone only to receive a phone call from him/her a short time later?
However, while the both of you miss each other, you are respectful of his marriage--this is why in your dream, you're looking for him but never find him but have the knowledge that he's looking for you.
Not that you're asking but my suggestion would be that it wouldn't hurt to get in touch with him and his wife--just to say hello. This might help you get a little more resolution when it comes to him. If your intentions are pure and respectful, you just may be surprised at the outcome.