The 58-year-old I, Tonya star was leaving the BAFTA Awards in London on Sunday night when she bumped into Prince William and Kate Middleton, and apparently treated them like friends she hadn’t seen in years.
Allison said she broke practically every royal protocol when she met the pair after a long night of partying.
Appearing on The Late Late Show on Wednesday, Allison told host James Corden, 39, she was standing outside on the street, barefoot with her heels in her hands, when the couple emerged from the Royal Albert Hall.
And while she definitely sounds like our kind of girl, Allison was left feeling a little embarrassed by how the whole encounter went down.
“I told her that I was in bare feet, and I told her that she should take her shoes off ’cause she’s pregnant, and it was an awkward moment,” she confessed, as reported by Glamour.
“[Kate] was in her heels and pregnant, so I felt like a bit of a wimp that I was there in my bare feet.”
Things only got worse from there, too...
"I called her 'honey', and that might've not been royal etiquette, probably," she added.
We didn't think it was possible, but now we love her even more.
She also recounted their meeting on Jimmy Kimmel Live.
"I said, 'Honey, you need to take those shoes off! Your highness, honey.' I called her honey!" she revealed.
"She smiled, I'm sure it was fine, but I was like, 'Really? I'm such a rude...' Like, 'Hi, honey! Take your shoes off.'"
WATCH: Allison Janney talks about meeting the royals at the BAFTAs. Post continues below.
But really, Allison said she was too busy just being amazed by how tall the 36-year-old Duchess is.
"She was in full-on heels and she was my height when I was in my bare feet. It was kind of extraordinary that she's that tall," revealed the 183-centimetre actress on The Late Late Show.
And while Allison may be feeling humiliated by her impromptu meeting, no one is more disappointed than her mum, who she says was "very upset" after hearing about her daughter's casual attitude towards the royal couple.
LISTEN: We take a look at whether I, Tonya is true to life, on our pop culture podcast. Post continues below.
Real talk though, Kate and William, 35, probably just enjoyed meeting someone who was so relaxed around them, because Allison says they couldn't have been nicer.
"They were lovely, she was lovely. They loved I, Tonya, and it was a pretty cool thing to meet them," she said.
It's official - Allison Janney is all of us. You know, if we were all movie stars who met royals...