In this work the authors present a clinical case in which the concept of loyalty to the memory of those who failed and the pain of that trauma can lead to symptoms that portends a psychological split, defined as a difficulty in family. The ethics and loyalty to family, loyalty to it to protect it from pain, sometimes sacrificing their own. The reading of the relational dynamics of family helps to highlight the function of the difficulty to define the child M. In this family, as often happens in families with children, M. was the clue to enter the maze of her painful family history and unravel the skein. This family has also helped the co-therapist to overcome their "mourning" about separation as co-therapists.
Keywords: Loyalty, family myth, authenticity, co-therapy, mourning, separation and belonging.

Alessandra De Col, Ilaria Picchio, Son alone, only a son, an only child? When loyalty to the memory of the brother and the pain of the parents is the consequence of a trauma with loss in "RIVISTA DI PSICOTERAPIA RELAZIONALE " 36/2012, pp. 85-98, DOI:10.3280/PR2012-036006