Kevin Mazur / TCA 2011 / WireImage 1 / 12
Kevin Mazur / TCA 2011 / WireImage 1 / 12

Was Selena Gomez a party pooper at Taylor Swift's 25th birthday? According to one magazine, that's precisely what she was, and it was was all over Justin Bieber.

While Taylor and other A-listers attending her party shared photos of the revelry via social media, Selena shared her feelings vocally, and it wasn't pretty.

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"She shouted, 'No one understands me! My boyfriend doesn't even understand me," an insider told Us Weekly, adding that bystanders -- "just stared [at her]."

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Selena's meltdown about her on-again, off-again boyfriend of three years unfolded on the upper terrace of Taylor's New York apartment in the Tribeca area, where fellow partygoers noshed on pizza and sushi and drank beer.

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The guest list for the "Blank Space" singer's birthday read like a who's who of entertainment: Justin Timberlake, Jay-Z and Beyonce, Sam Smith, Karlie Kloss, Nick Jonas and Olivia Culpo, Chrissy Teigen, 5 Seconds of Summer and others.

It appears that Taylor didn't let Selena's little tantrum get in the way of a good time, though, posting a photo on Instagram of the birthday shenanigans, saying, "So this is being 25…. #WHAT #bestbirthdayEVER."

In fairness, Selena did put on a happy face in another photo, standing next to her BFF as Taylor was presented with a birthday cake. Taylor Instagrammed the moment, captioning her photo, "When you're making a wish, but you already have all you really need standing around you."