A survey of therapists revealed that jealousy was the major problem in one-third of all clients seeking psychotherapy. Makes sense when you consider that it's one of the most complex and intense human emotions. Born of a cocktail of frustration, suspicion, envy, and sadness, jealousy can tempt you into totally irrational behavior, which you, in a better state of mind, would never consider or condone.
At the core, jealousy stems from insecurity. Talking about insecurity is one of the most vulnerable things a person can do. It's admitting to a belief that you are inadequate. It is never easy. But within a loving, supportive relationship, it will only ever change things for the better. On the other hand, if the issue of jealousy isn't resolved, your relationship will inevitably fail.