By Stan Tatkin and Tracey Boldemann-Tatkin // Secure functioning refers to an interpersonal system based on principles of true mutuality, collaboration, justice, fairness, and sensitivity. It means that you and your partner are in a foxhole together, protecting each other from the outside world… and from each other. Secure functioning assumes you and your partner have different minds, with different interests, drives, and histories. Secure-functioning partners are fully interdependent in the sense that each happily accepts the other as a burden, and both agree they are in each other’s care. In this kind of two-person system, you and your partner form a couple bubble, which you can think of as a protective boundary that protects your resources and sense of ongoing safety and security. Think of a couple bubble as an ecosystem or terrarium that provides you and your partner with the sustenance you need to carry out your daily tasks, deal with fears and anxiety, handle difficult situations and people, and undergo personal growth. In a secure-functioning relationship, you and your partner assure each …