Well, when you're this annoying, you don't even need to try ... and people get angry.
This time forthright Kelly Osbourne has unleashed a wave of fury on Horseface Hopkins after reading a vile story she published in her column last year regarding mama Osbourne, the X Factor judge Sharon.
Hopkins, writing about the X Factor final, wrote: "Sharon reckons her time on the panel may be up. Either way, if she is going to look this good next year she will need to bulk buy plastic."
But it seems Kelly's a slow reader and only came across these catty comments now. But that didn't stop her giving Katie a piece of her mind.
The 29-year-old angrily tweeted: "U R a hypocritical vile human that is addicted 2 attention U R so insignificant! Don't you ever talk about my mother again!"
Not only was her evaluation of Katie spot-on, she added the hashtag India – relating to Katie's daughter, who the reality star claims is not named after a geographical place.
And Kelly didn't stop there. In a furious post, she dropped the dreaded C-bomb, writing: "I know that what I am about to say is unbecoming of a lady and I'm sorry to say this but I can't lie you are a massive c***."
Well, this is the girl who grew up in the Osbourne house so we didn't expect censored insults.
Most people would ignore such a savage attack, but Katie couldn't resist sticking her oar in and provoking yet another celeb feud. She snidely replied: "No problem Kel. No one ever mistook you for a lady sweetie."
This snobby message riled Kelly even more and the Fashion Police star fired back: "You can shove your sweetie pie up your a** you insignificant t***! Karma will get you! bloody hell you are so such a sad a**."
Katie couldn't defend herself so decided instead to slag off Kel's career – despite the purple-haired babe having carved out an extremely successful TV presenting career on her own.
Horseface wrote: "Just like Peaches and Jesus, Kelly has done well due to a famous parent."
Thankfully, Kelly wasn't about to take this lying down, and posted: "Just like you can't help the parents you came from neither can I! I don't see you on a Forbes list I work my bum off nice try…"
And to finish off her outstanding tirade, she tweeted a picture of Katie getting frisky with a married man in a field, writing: "Says it all really."
Verdict: Kelly 1 Horseface 0