This C.O. was P.O.’d.

A corrections officer dumped a bottle of his own urine on a Rikers Island inmate after being splashed with the offender’s pee, according to a city administrative court ruling. 

Mezinski Merilus, 39, told superiors that he was escorting inmates back to their housing areas in November 2019 when he felt liquid land on his sleeve and neck.

In what he confessed was “a weak point,” Merilus, 39, admitted he then urinated into an empty Gatorade bottle and splashed it into the unidentified jailbird’s face.

Merilus was slapped with a 30-day suspension after the incident and had since been placed on modified duty with no contact with inmates.

Merilus, a former school safety officer from Queens who joined Corrections in 2011, later admitted he “let the situation get the best of him” and conceded his “actions were very, very excessive and wrong.”

He claimed he had grown since the incident, but city Administrative Judge Astrid Gloade still recommended his firing earlier this month.

“He was unable to control his anger and carried out a methodical and deeply disturbing plan to retaliate against an incarcerated person,” Gloade wrote in her decision. 

Gloade also pointed to the “ample time” Merilus had to calm down and abandon his fluid plan for revenge.

“Instead, over the course of more than two minutes, [Merilus] took a series of steps that show a troubling degree of uncontrolled anger and calculated retaliation,” the judge wrote.

Lawyers for Merilus argued he had faced “one of the greatest insults one can face” in a jail.

Gloade also cited Merilus’ disciplinary record, which included a domestic-violence arrest that cost him 30 vacation days in October 2017 and an excessive force charge that led to the forfeiture of another 10 days.

The guard’s past “offers little by way of mitigation,” the judge said.

The Corrections Department declined to comment on the case. Merilus, who is still on the payroll, could not be reached for comment.

“We strongly disagree with the OATH Judge’s recommendation to terminate our officer in this case. We are in the process of exploring all avenues to have this decision reconsidered, including an appeal,” said Benny Boscio, president of the Correction Officers’ Benevolent Association.