The fact is that the biological parent’s gain — a new romantic partner – is often experienced by his or her children as yet another in a series of family calamities. Remember that the stepchildren involved in remarriage situations have undergone early losses and often stressful transitions, such as a move out of the family home and to a strange school.

Also, the initial loss of the intact family – most likely due to divorce – has been experienced as a volcanic upheaval, inevitably bringing dee...