Not everyone loves pop sensation One Direction — just ask Justin Bieber.
The teen idol was fuming when girlfriend Selena Gomez flirted shamelessly with the boy band's heartthrob, Niall Horan, at the Kids' Choice Awards.
"Niall made a beeline for Selena and poured on the charm," a source tells Star. "When he looked into her eyes and said, 'You're beautiful,' Selena melted."
Justin, 18, looked furious. "He was stewing while it went down. He was ready to explode."
The incident just added fuel to the feud that was already brewing between the "Boyfriend" singer and One Direction, which made history when their debut album, Up All Night, hit No. 1 on the U.S charts. "I don't think anyone is taking my fans," Justin sniffed at the British band's success. "They're never going to betray me…."
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