Less than two weeks into the new year, we officially have our first celebrity feud of 2013!

It appears that Lady Gaga was not happy with some on-air jibes Kelly Osbourne made during her appearance on E! show Fashion Police, so she took to her Little Monsters website and put the TV personality on blast. In response, Sharon Osbourne stuck up for her daughter and responded with an open letter on Facebook.

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"I feel it culturally important to note that you have chosen a less compassionate path," said Gaga in her letter. (Side note: when have "Kelly Osbourne" and "culturally important" ever been linked together?!) "It used to make me truly sad when I would hear people talk about your weight when you were younger, as I was bullied too. To see you blossoming into a beautiful slender woman who makes fun of others for a living is astounding."

In response, Sharon took to Facebook over Gaga's "hypocritical" letter. "You say her work on E! with the Fashion Police is 'rooted in criticism, judgment, and rating people's beauty against one another.' Welcome to the real world," wrote Sharon, according to E! Online. "You have shown me that you are nothing more than a publicly seeking hypocrite and an attention seeker... Let me know if you want to continue this debate. I'm an open playing field for you my darling."

Your move, Gaga.

Whose side are you on in this battle?

Photos courtesy of Getty Images