The new series of the E4 show begins this Monday night.
Hunky model Calum is one of the celebs on the new line up but finding him a match proved difficult.
Speaking on Sunday Brunch, Nadia revealed: "[Calum] was one of the worst the reason is, he gets so many girls that he thinks he doesn't have to try, to learn.
"So he came in with all the banter, all the chat, and literally the first few dates are horrendous because he just can't get it together."
Meanwhile the Celebs Go Dating 2017 cast are definitely single this time around, after Stephen Bear's lies.
The last series turned into a bit of a farce when it was revealed that Bear was dating Charlotte Crosby at the time.
It led to him being kicked out of the dating agency by Nadia and she's determined not to let the same thing happen again.
Speaking ahead of the new series, Nadia said: "We’ve done more vetting, in terms of more checks on social media, and more checks on who, what, where, when – and at the end of the day, if someone wants to come in and say they’re single when they’re not, that’s on them.
"We can only do so much. But they are cheating themselves out of a really important opportunity."
Alongside Calum, other celebrities taking part in Celebs Go Dating's third season include TOWIE's Bobby Norris, TOWIE star James ‘Arg’ Argent, Model Calum Best and X Factor's Frankie Cocozza.
As for the girls, reality star Charlotte Dawson, TV presenter Sarah-Jane Crawford and Made In Chelsea's Georgia Toffolo have all also been confirmed for the show.
Series three of Celebs Go Dating starts on Monday, September 4.
The show is expected to air each week night for four weeks like the firs two series, so that's 20 episodes in all.