" The boundary between caring and incestuous love is crossed when the relationship with the child exists to meet the needs of the parent rather than those of the child. As the deterioration in the marriage progresses, the dependency on the child grows and the opposite-sex parent's response to the child becomes increasingly characterized by desperation, jealousy and a disregard for personal boundaries. The child becomes an object to be manipulated and used so the parent can avoid the pain and reality of a troubled marriage.
The child feels used and trapped, the same feelings overt incest victims experience. Attempts at play, autonomy and friendship render the child guilt-ridden and lonely, never able to feel okay about his or her needs. Over time, the child becomes preoccupied with the parent's needs and feels protective and concerned. A psychological marriage between parent and child results. The child becomes the parent's surrogate spouse. "

― , Silently Seduced: When Parents Make Their Children Partners - Understanding Covert Incest