Miley Cyrus and Selena Gomez's seven-year feud seems to be hitting its peak.

Apparently, the former Disney stars are again engaged in an Instagram war following an altercation during Cody Simpson's 18th birthday celebration.

"Miley and Selena got at it at Cody's birthday party," the alleged source of Hollywood Life revealed.

Adding, "Miley said something about Cody having to have two different birthday parties in order to cater to Selena who didn't want to have any run-ins with Justin [Bieber]."

While the feud was fueled because of Miley's "brotherly" love for Bieber, Nick Jonas, who was allegedly romantically involved with both Selena Gomez and Miley Cyrus, is reportedly annoyed with his former lovers' unending fight.

"Nick's teeny bopper days feel like ancient history to him. He doesn't spend one second of his life thinking about Miley or Selena as he's too focused on his future. Nick wants to be taken seriously as a leading man in Hollywood so to have his name dragged back into some junior high school feud is really frustrating," an alleged insider of Hollywood Life claimed.

Adding, "Nick's completely moved on and thinks Miley and Selena should too. They should get over any problems they had with each other when they were kids. It's time for everyone to grow up."

And while Nick Jonas wants Miley and Selena to get over their feud, new reports claim that the "Come & Get It" singer was reportedly trash talking the "Wrecking Ball" hitmaker.

"Miley actually has never hooked up with Justin but she loves that Selena thinks she has. Miley doesn't see Justin that way, they're just friends, they're like family, but she's happy that Selena is threatened - anything she can do to get to her," Sugarscape quoted an alleged Hollywood Life source.

Adding, "[Miley] hates everything about her. She thinks Selena is the biggest hypocrite of all time, she acts like she's so perfect - like she's this goody two shoes - when she's partied just as much as anyone, she just keeps it on the down low."

"Selena forbid Justin from hanging out with Miley and turned a lot of their mutual friends against her. Selena would call Miley 'trailer-trash' behind her back. Miley got really sick of her being so two-faced."