Rep. Katie Hill admitted this week that the relationship she had with a staffer was “inappropriate,” amid allegations she was involved in a “throuple” with her husband and the subordinate.

The California Democrat said Wednesday that she became involved with the campaign worker during the “final tumultuous years” of her abusive marriage to Kenny Heslep, the National Review reported.

“I know that even a consensual relationship with a subordinate is inappropriate, but I still allowed it to happen despite my better judgment,” Hill said in a statement. “For that, I apologize. I wish nothing but the best for her and hope everyone respects her privacy in this difficult time.”

Hill, who is openly bisexual, had previously slammed reports that she was involved in a three-way relationship as a “smear campaign” after intimate photos were exposed by the conservative outlet RedState.

“The fact is I am going through a divorce from an abusive husband who seems determined to try to humiliate me,” she told The Post in a statement. “I am disgusted that my opponents would seek to exploit such a private matter for political gain.”

She also said claims that she had a solo affair with her legislative director, Graham Kelly, were “absolutely false.”

“I am saddened that the deeply personal matter of my divorce has been brought into public view and the vindictive claims of my ex have now involved the lives and reputations of unrelated parties,” she said.

The House Ethics Committee announced Wednesday it launched an investigation into Hill’s romantic life.

“The Committee is aware of public allegations that Representative Katie Hill may have engaged in a sexual relationship with an individual on her congressional staff,” the committee said in a statement.

“The Committee… has begun an investigation and will gather additional information regarding the allegations.”