From experiance...
your husband still has strong feelings for her. It seems there was never any closure, which means she caused the relationship to end without his say so in the manner.
Im not saying you were the rebound, but take a look back as to how fast your relationship went, did you get married within a short period of time, did he try to impress you continuously maybe trying to make someone jealous, does he now still try to impress with items such as cars, cloths items of fashion?
Ask yourself, is your marriage going where you want it to, or is he putting it on the back burner....this is a sign he was not ready and is scared to tell you now to go forward. This is like when a woman is ready to have a baby but a guy is not.
Ok you get the idea...best of luck
[qtpiemom]