Longtime Backstreet Boys fan Kitty Tung was in for quite the surprise when she recently attended a meet-and-greet with boyfriend James Guan at the band's Larger Than Life residency show in Las Vegas. Not only did the Backstreet Boys help arrange an epic proposal for her, but they also serenaded her while her boyfriend got down on one knee. "When the Backstreet Boys started singing, I was trying to remain calm, but my heart was beating so fast. It was so surreal and I couldn't believe that the Backstreet Boys helped him pull this off," she told ET. The couple have been fans of the Backstreet boys for years now, so it was only right that they played a part in their special moment.