Don't expect to spot Kelly Osbourne at a Lady Gaga concert anytime soon.
"While I wish you had reached out to me personally, as the head of the Born This Way foundation with my mother Cynthia, we would like to respond," Gaga begins. "Everyday, through my music and public voice I choose to be positive and work towards a kinder and braver world with our community of followers."
The tone, however, quickly changes when the superstar turns the finger at Osbourne's E! Fashion Police hosting gig.
"I have empathy for you Kelly, but I feel it culturally important to note that you have chosen a less compassionate path," she writes. "Your show breeds negativity, and over the years has even become comedic in nature. It glorifies you and Joan Rivers pointing in the camera, laughing, and making jokes about artists and celebrities as if we are zoo animals."
She ends the letter by apologizing for her fans' behavior, but asks the E! host to reevaluate herself.
Needless, to say Osbourne was not pleased: "Hope you guys realize that I don't care about any of this bull----! I know who I am I don't need anyone to tell me," Osbourne Tweeted.
But the star's mother, Sharon Osbourne, had some choice words for Gaga, calling the singer a "hypocrite" and an "attention seeker" in her own open letter. The America's Got Talent Judge writes, "I am calling you a bully because you have 32 million followers hanging on your every word and you are criticizing Kelly in your open letter. Are you so desperate that you needed to make this public?"
She concludes: "A word from you would stop all the hideous, negative and vile threats from your 'little monsters.' "
The younger Osbourne used a quote from one of Hollywood's most famous stars to conclude the rift, Tweeting: "'When a man gives his opinion, he's a man. When a woman gives her opinion, she's a bitch.' – Bette Davis."
Osbourne's Fashion Police costar, Joan Rivers, also chimed. "Fashion Police is a comedy show; anyone that comes out of an egg should figure that out," she told E! Online, referring to Lady Gaga's arrival to the 2011 Grammy Awards.