Ladies’ man Josh Hartnett has struck again! After romancing Scarlett Johansson and Helena Christensen, Hartnett, 29, was spotted locking lips with the “Umbrella” singer, 19, last night at NYC club Pink Elephant, a witness tells Usmagazine.com. A source says the couple — who lunched about three weeks ago in L.A. -- met up after her Thursday night concert at the Nokia Theatre in Times Square. The duo, who were sipping Dom Perignon and Pink vodka throughout the night, “didn’t come together, but left together,” the witness adds. New couple alert? Stay tuned!