Venus Williams is fed up with her younger sister and doubles partner Serena Williams’ partying, a report said Wednesday. The tennis stars have reportedly ignored each other at recent public appearances.

“They’re not in a good place right now,” a source told the New York Post’s Page Six. “Venus is angry with Serena.”

Venus and Serena Williams arrived separately to the “Taste of Tennis” kickoff event ahead of the U.S. Open in August, the report said. Once there, the pair reportedly didn’t speak. “There was no acknowledgement that either one was even there,” a source told the newspaper.

Serena Williams was active in the New York City party scene ahead of the Tuesday launch of her new HSN clothing line at New York Fashion Week. Over the past several days, the 32-year-old was spotted partying with actor Joe Jonas, model Gigi Hadid and fellow tennis star Caroline Wozniacki.

It has been months since Venus or Serena Williams posted about each other on their popular Instagram feeds, Page Six notes. Moreover, Venus Williams wasn't seen in attendance at Style360 Lounge for a presentation of her sister’s clothing line.

The sisters have struggled as doubles partners over the past few months. The pair withdrew from Wimbledon this year after Serena Williams suffered from a mystery illness, and they lost in the U.S. Open quarterfinals on Sept. 2.

Representatives for both sisters denied rumors of a rift this week. “I am very surprised by these accusations. They are completely false. Venus and Serena always have been and continue to be close and supportive of one another,” Venus Williams' rep, Lisa Sorensen, said, noting that her client couldn’t attend the launch of her sister’s clothing line because she had to prepare for the Quebec City WTA Open.

Meanwhile, Kelly Bush Novak, who represents Serena Williams, referred to Page Six’s story as an “absolute lie." “They continue to be each other’s biggest fans and a beacon of support for each other,” Novak said. “There is no change in their very close and special relationship."

Even if it's true, Serena Williams’ partying hasn’t affected her tennis game. She defeated Wozniacki to win the U.S. Open singles title on Sunday -- the 18th Grand Slam victory of her career.