The U.S. Court of Appeals for the First Circuit recently considered the circumstances under which an employer can be held liable for sex discrimination for terminating an employee whose job performance has been maligned by a jilted co-worker intent on revenge.

In Velazquez-Perez v. Diversified Developers Realty Corp., the court found that the plaintiff had made a plausible case that he was terminated at the insistence of the company’s human resources manager, who was not in his supervisory chain, after he had rejected her sexual advances.

The First Circuit laid out a three-part test. “An employer can be held liable under Title VII if: the plaintiff’s co-worker makes statements maligning the plaintiff, for discriminatory reasons and with the intent to cause the plaintiff’s firing; the co-worker’s discriminatory acts proximately cause the plaintiff to be fired; and the employer acts negligently by allowing the co-worker’s acts to achieve their desired effect though it knows (or reasonably should know) of the discriminatory motivation.”

At first, Velazquez-Perez and the human resources manager, Rosa Martinez, had a good working relationship. Their relationship was flirty at times. Martinez made a series of romantic advances toward Velazquez-Perez, which he rebuffed. After Martinez followed Velazquez-Perez and confronted him on a mutual business trip, he informed her that he did not want to pursue a serious relationship with her. Martinez then made statements insinuating that she would have him fired for rejecting her.

Velazquez-Perez complained to his management about Martinez. In response, his supervisor advised him to send Martinez a conciliatory e-mail or “she’s going to get [him] terminated.” His supervisor also jokingly suggested that he have sex with Martinez.

Ultimately, Martinez raised the alleged problems with Velazquez-Perez’s performance to the upper levels of the company’s management and got his employment terminated.

In light of this decision, employers are advised to take seriously any romantic relationships or sexual advances between co-workers, and to be careful not to permit jilted co-workers to take revenge through employment actions. Supervisors should be reminded to report, document, and investigate all employee complaints, even if they seem trivial.