The pregnant singer appeared on Thursday's May 14, 2020 episode of the show, filmed before the coronavirus shutdown, and stunned judge Jock Zonfrillo by asking him to cut up her food so she didn't need to use her sprained thumb.
"Will you cut my meat for me?" she asked before trying a braised pork dish.
The Scottish chef indulged her request, prompting Perry to say, "Party in my mouth! Put it in my mouth, Daddy!"
The comment prompted gasps from the show's contestants and judges and left those watching at home speechless.
"Did she just say put it in my mouth Daddy?" one fan tweeted.
Another added, "Hopefully Katy Perry's #MasterChefAU legacy is not the theme song but everyone calling Jock 'Daddy.' "
Perry's lighthearted comments included jokes about her eating for two.
"Well, me and my unborn child are ready to eat!" she said after she arrived in the kitchen. "You have two mouths to feed."
The star is set to welcome her first child with fiance Orlando Bloom.