This case is taken from Kenneth A. Strike and Pamela A. Moss, Ethics and College Student Life: A Case Study Approach, 2nd ed. (Prentice-Hall, Columbus Ohio).
CASE 6.4 Cheating (p. 134)
Nick and Katie have been a couple for two years, and despite some minor fights, they feel firmly committed to each other. They often talk about getting married eventually and have even planned many details of their future life together. One night when Katie went out with her girlfriends, Nick met Olivia at a party. Olivia was very sexy, exotic, temperamental, and rather wild--everything that Katie was not. Nick and Olivia began an affair almost at once. Nick knew, even while he was "in lust" with Olivia, that he had no intention of dropping Katie for her. Katie was the person he wanted to marry someday, and Olivia was merely the person with whom he wanted to do unprintable things right now. Therefore he took great care to avoid making Katie suspicious, and he saw Olivia only on the sly, when Katie thought he was studying or out with his friends.
In fact, no one knows Nick's dirty little secret except for Linda and Omar, mutual friends of Nick's and Katie's who saw Nick and Olivia embracing passionately under a tree. Linda and Omar argue about whether or not to tell Katie what's going on. (They don't know Olivia, and they feel no loyalty to her.) Omar thinks it's none of their business; perhaps Katie already knows about it and has decided to ignore the affair until it blows over. "We'll just embarrass them both if we tell her what we saw," he says. "And maybe this is something Nick just needs to get out of his system."
Linda disagrees. "He has no right to treat Katie like this! When I see Katie with Nick, I'm sure she doesn't know. And she would never forgive us if she found out that we knew and didn't tell her."
Comments and Considerations
In the "Cheating" case, the chief persons whose acts or possible acts should be evaluated are (1) Nick and (2) Omar and Linda. If what Nick is doing in relation to Katie is "cheating," how should we define cheating? Perhaps it would help to think of Omar's and Linda's position in relation to Katie in the context of friendship. Maybe there is a prima facie duty of fidelity to help our particular friends in ways we would not be obliged to help random individuals (similar to the way in which we have duties to keep our promises to particular individuals).