triangulation is the unhealthy mechanism that entangles three individuals into a pattern or system: it often "pulls together" a sense of loyalty and maintains balance. Alliances form, creating an unspoken way of interacting and behaving; taking sides and creating rivalry. When the triangulation is stopped, anxiety actually increases, as it is a new way of being, unknown and foreign. The process of separating into autonomy is called differentiation.
Every ecosystem struggles to maintain homeostasis. Whether it's a terrarium or a glass of water seeking its own level. In terms of human beings, overtime, we develop patterns, norms, and roles, often unspoken. When any new change is attempted, even if it's healthy, there is always push back. This is normal, and if you can expect that, you are able to respond patiently for the healthy change to take root.
Three's a crowd. Third wheel
(ever see three teenage girls struggle to get along?)
Example: Mom secretly gives adult son money. They now have a private relationship that excludes dad. Mom continues to feel important and needed via her enabling. Dad will grow angry and pull away from his wife, feeling undermined and harmed by their alliance deceit.
The mother/father/child triangle is commonly seen in blurred boundaries, enmeshment, and fusion.
In the case above, if Mom and Dad strengthen their relationship, the adult son will act out negatively and employ old tactics to bring the system back to something that feels familiar..