In this work the authors describe a clinical case, conducted in co-therapy, which is highlighted a particular configuration relational: Emotional Tetrad In the co-therapy of couple there is the risk to incur in this relational configuration, especially if the co-therapists share with the couple common aspects of life. Within the therapeutic relationship, particular attention is put on the emotional resonance of the co-therapists used as resources to overcome the therapeutic impasse. Key words: emotional tetrad, emotional resonance, bridge-communicative, cotherapy, therapeutic impasse