Someone mistakenly thinks Phyllis is pregnant and there is no father

[Caracci]

Hi everyone!
I'm trying to find a specific scene from The Mary Tyler Moore Show
or the spin-off Phyllis with Cloris Leachman as Phyllis Lindstrom.
In this scene, there's a misunderstanding triggered by the phrase
"I'm waiting for my pupa" (or something similar), leading someone to
mistakenly think Phyllis is pregnant. The scene involves a living
room with several people, then Phyllis opens a door on the left side
of the screen to a maybe male visitor.
It's a short scene from about 40 years ago and I could have lost or
changed some details. Does anyone remember this episode or scene?
Thanks so much!