My aunt, with whom I live!

The following comedy skit has a hilarious punch line in the end.
This is from "Not the Nine O'Clock News," a television comedy sketch show.

Here goes the clip with my Japanese subtitle:

A student is asked to correct his grammar by clarifying the usage of preposition when used with the relative pronoun.

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from "my aunt, who I live with"
to "my aunt, with whom I live"
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The shift, putting "with" before relative pronoun "whom" (formal version of "who"), seems to be a tiny little difference, but is often treated as one of the formal styles of composition.

The punch line is funny as it betrays the expectation audience would have had by then.
The student's recycling of the same sort of answer to any test question is surely expected to be the target of teacher's condemnation, but what infuriated him was the student's repetition of the casual phrase "my ant, who I live with."  

To be continued.