Looks like Chris Brown's bizarre love triangle may still be in full effect in 2013. Onlookers (and fans) were confused when Brown was given the very cold shoulder by on-again love Rihanna at Hollywood club Playhouse past midnight on Friday (Feb. 15). But Rihanna's ire could be explained by Brown's apparent party companion the evening before: Karrueche Tran.

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Making a surprise appearance at the Topshop/Topman launch party at Cecconi's in West Hollywood on Wednesday, Brown was among many A-listers:  Kim Kardashian and Kanye West, Kate Bosworth, Kris Jenner, Emma Roberts, and Kelly Osbourne, plus Jennifer Lopez and beau Casper Smart. But according to one source, Brown's date for the night was model Tran, 24. Brown and Tran split in October 2012 after a rollercoaster, yearlong relationship, which was marred by Brown's secret trysts and growing closeness to ex Rihanna.

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"It was very hard," Tran told Rolling Out magazine of the ordeal. She and Rihanna butted heads more than once during the saga via Twitter. "I try my best to just ignore the negativity, which is hard for me because it's a lot to deal with. But I try to keep a positive mind and stay strong and not put energy into it."

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Arriving at Playhouse with a 20-deep posse the night after hanging with Tran, Brown didn't seem to be "on speaking terms" with Rihanna, one observer said.

"She refused to sit with or even near him," the witness explained of the twosome, who seemed inseparable at Sundays Grammys. "When she noticed he was there, she made a huge show of rubbing her presence in his face."

This article originally appeared on Usmagazine.com: Chris Brown Partied With Karrueche Tran Night Before Rihanna Ignored Him