5 Seconds of Summer recently released a new single “Older,” which features frontman Luke Hemmings’ fiancé Sierra Deaton’s vocals. “Stare at the photograph/Suddenly takes me back/The promises roll off your breath/In your cocaine-colored wedding dress,” Deaton and Hemmings sing in the first verse. “Lost in the day-to-day/You kiss away the pain/Oh, every time you twist…