The dream about marriage to an ex-boyfriend is a sign of a personal life. You can again trust that man and even get married with him in reality. Old grievances will recede and make room for fresh emotions.
If you had the dream of the death of an ex-boyfriend this personifies an internal riot. You cannot reconcile with parting and constantly return your thoughts to happy life together with him. You need to learn to live without this person: take some free time, find new hobbies and interests. It will help to overcome the pain and forget the past.
The dream in which you are hugging an ex-boyfriend shows a longing for a relationship with him. Perhaps you feel the incompleteness of the relationship or their understatement. To get rid of such thoughts, try to write them down on a sheet of paper and burn it. The same is the dream interpretation in which the ex-boyfriend finds a new love interest.