Issues regarding infidelity are examined in terms of antidotes for avoiding unfaithful behavior. Several self-assessment activities are described in which couples can be honest and direct with each other about their perceptions and experiences with commitment and fidelity both as children and adults. These activities are intended to act as booster shots to build antibodies counter to unfaithful behaviors in long-term relationships. The activities can be used as prescriptions by mental health professionals with couples who are considering marriage or who are already married and experiencing concerns about maintaining a long-term, faithful relationship. Throughout the article, references to the closely related notion of commitment are discussed resulting from a survey of individuals' views of commitment in romantic relationships.