Kim Kardashian and Beyoncé Ignore Each Other at Jay-Z Concert

While it's been rumored that Kim Kardashian and Beyoncé aren't exactly best friends, it appears the tension reached all-new levels this Labor Day when the two women barely spoke at a concert in Philadelphia.

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Kim K. tagged along with Kanye West to the Made in America festival, where Jay-Z performed. She was met by a chilly silence from Jay-Z's wife.

“Kim and Beyoncé barely spoke to each other,” a souce at the concert told The New York Daily News. “They were on opposite sides of the stage. Beyoncé didn’t even acknowledge Kim was there until the concert was almost over.”

Ouch. What a difference three months make. This past June, Bey and Kim were inseparable during the British leg of Jay and Kanye's 'Watch The Throne' tour, but that could have just been basic politeness.

Then the two ended up together in the dressing room. "You could tell Kim was uncomfortable.... She clung onto Kanye the entire time and didn't say much," she spy reported, adding that she opted to talk to her publicist friend, Jonathan Cheban, instead.

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Those close to Bey probably aren't surprised she hasn't warmed to the reality star.

"Beyoncé’s not happy about Kanye’s relationship with Kim," a source told The Sun. "She had a conservative upbringing, which was very different to Kim’s. Bey’s never been impressed by Kim's record with men and the sex tape that leaked a few years ago. Her 72-day marriage doesn’t exactly inspire her with confidence that Kim wants the relationship with Kanye to last, either."