The Project asked Paris Hilton about Rob "Millsy" Mills, and it was painful to watch.

Attention: Paris Hilton is in Australia and even though we haven’t seen her for 10 years she hasn’t changed at all.

Sorry. Just had to get that out of the way.

The 35-year-old socialite, DJ and businesswoman appeared on Thursday night’s episode of The Project to discuss her new perfume and the US presidency… but mostly her perfume.

Things got awkward, however, when Ryan ‘Fitzy’ Fitzgerald started to ask Hilton about her relationship status. “I’m very single,” she said, when Fitzy joked about having a few mates who were wondering.

But then he asked her something very specific.

"This is an old flame, but I'd just love to know..." he started. "Do you keep in contact with Millsy, Robert Mills? Remember, Millsy?"

Her response could not have been more blank. It was like the moment Mariah Carey was asked about Jennifer Lopez and maintained, "I don't know her."

Hilton just looked like she had never in her life heard of anyone called Robert... or Millsy... and certainly not 'Robert Mills.'

She continued to shake her head, said "No," and then looked to the audience to shrug.

That's some serious shade GURL.

Of course, Paris Hilton and Rob Mills had a fling in 2003, when Hilton was in Sydney. Late last year Mills told Em Rusciano they met at an Opera House after-party for the Australian Idol finale, and "hooked up" at an after-after party at Osher Gunsberg's house.

He was infamously snapped the next morning when he stepped out onto the balcony of Hilton's hotel room.

They continued to spend time together for the two weeks she was in the country, and they met up again a year later when Hilton visited Australia.

...But do you want to know the most awkward thing about this whole debacle?

On Thursday night, Rob Mills' MUM was in the AUDIENCE of The Project. Co-host Peter Helliar shared a post on Instagram about the moment he came to that realisation.

So @ParisHilton visited us @theprojecttv tonight!! She was lovely. We got a selfie and then she took a selfie with our newly engaged couple in the audience. But the INTERESTING thing about this audience pick is the woman sitting behind them trying to avoid being in shot is none other than the MUM of MILLSY!! We only found out after this pic was taken and after Paris had left. Totally coincidental. #paris #parishilton #goldrush #gold #tv #millsy #mum #live #laugh

A photo posted by Pete Helliar (@pjhelliar) on Nov 17, 2016 at 2:44am PST

Captioning a photo of the audience, he wrote: "the woman sitting behind them trying to avoid being in shot is none other than the MUM of MILLSY!!"

"We only found out after this pic was taken and after Paris had left. Totally coincidental."