Tom suggests that couples in romantic relationships would be wise to adopt explicit, or at least quasi-explicit, contracts specifying what activities constitute violations of trust. Agreeing that “If you should engage in any touching of lips or genitalia with someone else, you must inform me before the next time we engage in similar activity” establishes a bright-line rule that coordinates the expectations of both parties.
During the break in Tom’s lecture, Steve H. observed that the above rule makes most sense in a semi-casual “college” relationship. For more committed relationships, more restrictive rules would be justified, because a broader range of external interactions would constitute a breach of trust. Suppose, for instance, that your husband has lunch with a young woman – let’s call her Sara – and they spend their entire meal staring at each other with storms brewing in their eyes. But nothing more happens. Has the commitment been violated? How could a vague rule against “romantic attractions” be properly interpreted or enforced? The problem is that the crime, if any, consists entirely of mental events. Fights could easily ensue from the failure of the rule to coordinate expectations on verifiable aspects of the external world. Even a highly committed couple might do better with a less restrictive but more objective rule (“no touching of lips or genitalia with other people”), or perhaps a more restrictive and more objective rule (“no lunches with members of the opposite sex without prior notice and consent”).
A simplistic way to deal with the problem is to say that any relationship requires trust and good faith. That should go without saying. The point is that even a relationship with sufficient trust and good faith could suffer from divergences of expectations, which can erode the underlying trust. Bright-line rules, in personal relationships as well as in law, can serve an important function.