Police are looking for any unsuspecting customers who may have purchased a urine-laced milkshake from an Arby’s in Vancouver, Washington, late at night last October. The unusual search comes after Stephen Sharp, who was a night manager at the fast-food joint at the time, admitted to relieving himself in the milkshake beverage mix for “sexual gratification,” according to the New York Post. Sharp made the admission as part of an investigation into child-pornography charges. Any customers who may have consumed the drinks are urged to contact authorities, but only if they still have the receipt to prove the purchase. Police are also investigating whether employees knew of the manager’s fetish and failed to report it.