Katie previously branded Sam a "fat mum in a jumpsuit", but Sam later told us that she was "bigger and better" than getting in a war of words with the controversial star.
However, she must have had a bit of a change of heart following Katie's latest attack, which saw her write on Twitter: "Jesus. John Lewis has a sale on jumpsuits 'one size too small'. Has anyone told Sam Bailey?"
Sam then took Katie to task, writing: "It's getting very boring now, hun x."
Oooh, we just love the patronising use of 'hun'. Well played, Sam!
If rumours are to be believed, Katie is currently gearing up to enter the 'Celebrity Big Brother' house on Friday, as she is reported to be one of the housemates forming the "most controversial line-up ever".
Meanwhile, Sam's lost out on having the last number one of 2013, as her single 'Skyscraper' was pushed down to number two by Pharrell with 'Happy'.
There was no hard feelings though, as she tweeted: "Well done @Pharrell for the number 1 spot xx love it xxx."