Spiteful functionality (“spiteionality” for short).
In German that is the well known and rightfully dreaded Vorführeffekt. The Vorführen means showing how somethings is or works, only, when you do show it, it does not show what you intended but fails miserably. In English I would call it the “let-me-show-you” or demonstration effect.
As for the OP: what you are looking for is how to say “oh please don’t make me look like an idiot” more concisely. Sounds like a garden variety of the inferiority complex. There probably is a cure for that, but somebody who writes Semper Gloriosus! next to their name should not need it. Which is just as well, as I can’t think of neither the concise expression nor the cure right now.
This wins the thread.