First, try to determine what they are " getting " out of the contact
and relationship. In every ongoing human relationship there is
usually " something " you get. It may be attention, love,
money or any number of things, but as the source
dries up or loses interest the contact breaks off.

That is a big reason why marriages go sour. When the "something"
that one or both partners were getting and expecting slows or stops
they wander off in search of a new source for that specific "something".

Allow the young person to exercise self improvement on their own.

• Identify their need for the relationship.
• Replace that need if possible.
• Don't talk down to them.
• Don't try to force them
  
• Be understanding.
• Be open minded.
• Be supportive.
• Be loving.
• Be fair.