Earlier this week, Mitch pranked 24-year-old Charlotte by tweeting from her account: 'OMG I said yes.'
Immediately Twitter went into meltdown, assuming the Geordie Shore star was engaged.
But Charlotte later revealed the truth, insisting she was not getting married.
Now Katie, 40, has claimed Mitch is not right for Charlotte. Writing in her column for The Sun, she said: "I am relieved to hear that Charlotte Crosby isn't engaged.
"I sat behind her and Mitch at The X Factor and he was all over her like a rash. Charlotte didn't seem so keen.
"Mitch mat be A one, but he definitely isn't THE one."
After Mitch's joke, Charlotte tweeted: "Soooooooooooo don't ever let your Boyfriend get your phone when your drunk. I'm not engaged. And believe me he will be punished today [sic]."
Even Charlotte's showbiz pals were tweeting messages of congratulations. Replying to Samantha Faiers, Charlotte said: "God Sam! I could kill him I've woken up to the world thinking I'm engaged [sic]."