Thank you for your kind elucidation, Jafar, but what I said was:
The term "irregular" refers to a category of food, not an adjective.
There is no reason the label "irregular" has to do with taste (or a 'bad' food texture, for that matter,) contrary to what SPD Officer said.
And, therefore, the reason for Moe's "oh" reaction was something else nasty, indeed, left to the imagination. And that's part of the joke.
It appears Squishee Lady "got it." Now you do, too!