Going down on a what?
Oh, never mind. I'm reminded of the limerick, in which the guy charged with indecent exposure had his charge dismissed due to insufficient evidence:
Whenever a fellow named Rex
Flashed his very small organ of sex,
He always got off,
For the judges would scoff:
De minimis non curat lex.*
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* The law does not concern itself with trifles.
If only that was still true...