Melissa Nelson worked as a dental assistant for Dr. James Knight for more than ten years. During the last year and a half of Nelson's employment, the dentist began complaining to Nelson that her clothes were tight, revealing, and distracting. Knight and Nelson also began to text one another on work-related matters as well as personal matters. Some of the texts included sexual references. The dentist's wife, who worked in the dental office, became aware of the situation and insisted that her husband fire Nelson because she was a threat to their marriage. Knight subsequently fired Nelson, telling her it was because their relationship was a "detriment" to his family and "that for the best interests of both [him] and his family and Nelson and her family, the two of them should not work together." Nelson received one month's severance pay.

Nelson's husband called Knight to talk about the firing, and Knight told him that Nelson had not done anything "wrong or inappropriate and that she was the best dental assistant he ever had"; however, Knight said he was afraid he was getting too personally attached to Nelson and "feared he would try to have an affair with" her at some point. Nelson then sued Knight for "discrimination against her on the basis of sex." Is a male employer who fires a female worker because his wife thinks their consensual relationship threatens their marriage liable for sex discrimination? Is it relevant that the dentist has never had a male dental assistant? Would it matter if Nelson had been a yoga instructor instead of a dental assistant? Does "sexual favoritism" constitute sex discrimination? If Nelson had instituted a sexual harassment claim or a hostile work environment claim, what would the outcome have been?