Justin Bieber snubbed the WRONG WOMAN … refusing to take a picture with Ronda Rousey‘s little sister — so says Ronda who claims Bieber was super rude about the rejection.

Ronda says it all went down at the Cannes Film Festival in 2014 — where Ronda and her 16-year-old sister say they saw Bieber at a media event and approached him for a photo.

Ronda tells she thought Bieber would be open to the pic since they were all at a media event and “everyone’s taking pictures today.”

But what ensured, according to Rousey, was pure snubbery … and clearly, Ronda still holds a grudge.

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