justified during his set at the opening of the Fontainebleau in Las Vegas on Wednesday evening.The 42-year-old *NSYNC member seemingly cautioned concertgoers before singing his 2002 hit “Cry Me a River.”“No disrespect,” he yelled to the audience before performing the single.The Timbaland-produced track was mentioned in Timberlake’s ex-girlfriend Britney Spears’ recent memoir, “The Woman in Me.”“Cry Me a River” was off of the “Mirrors” singer’s solo album “Justified” and the lyrics crooned about his breakup with Spears.“I felt there was no way at the time to tell my side of the story,” the “Toxic” songstress, 42, penned in her bombshell autobiography.She went on: “I couldn’t explain, because I knew no one would take my side once Justin had convinced the world of his version. I don’t think Justin realized the power he had in shaming me.