The court Friday upheld a lower court ruling in December that Dr. James Knight acted legally when he fired dental assistant Melissa Nelson in January 2010 after his wife became concerned about the relationship between the two, CNN reported.
Knight's conduct did not constitute sex discrimination under the Iowa Civil Rights Act, the court said.
"In the former case, the decision is driven entirely by individual feelings and emotions regarding a specific person," Justice Edward Mansfield wrote in the court's ruling Friday. "Such a decision is not gender-based, nor is it based on factors that might be a proxy for gender.
"While the loss of a job is often devastating to an employee, and at times unfair, these considerations do not play a role under our employment-at-will doctrine, and our exceptions to this law, such as sex discrimination, are only based on the underlying discriminatory motivation of the decision maker," he said.
Knight apparently told Nelson's husband that the dental assistant, who had worked for him for 10 years, was a threat to his marriage because he feared he would attempt to have an affair with her, The Des Moines (Iowa) Register reported.
Nelson's attorney, Paige Fiedler, said in a statement Nelson was "beyond distressed at the lack of awareness and understanding this decision demonstrates."