June 9 (UPI) -- Katy Perry and Justin Trudeau are making their romance red carpet official. The singer-songwriter, 41, and the former Canadian prime minister, 54, attended the Tribeca Film Festival premiere of Perry's concert film Katy Perry: The Lifetimes Tour - Live from Paris on Monday. Perry and Trudeau were all smiles as they posed for photos, with Trudeau appearing to briefly rest his hand on Perry's stomach before caressing her backside. In a Q&A after the screening, Perry called Trudeau