Relationship patterns before and after pathological gambling were investigated qualitatively using eight in‐depth clinical case studies in which one partner met Diagnostic and Statistical Manual of Mental Disorders‐IV pathological gambling criteria. Five circuits of couple interactions are described: (i) fault‐lines; (ii) pressure points; (iii) escalation; (iv) relapse and (v) congruence. The exploration of these circuits is developed in two complementary articles. This first article delineates the first four circuits as recursive self‐perpetuating cycles of couple distress in systemic interaction with pathological gambling development and relapse. The second article delineates how a couple can be helped to extricate themselves from these recursive circuits through ‘congruence’. Implications of this relational formulation of pathological gambling for conceptualization, assessment and treatment are discussed.