Yup, this is a contest for the longest and most improbable but grammatically correct sentence punning the word pun. Puns should be more or less in the region of English but other languages can be used if there is enough currency. Criteria for longest is basically the most number of puns on pun and no repetition of the same pun.
This is what I came up with.
The punter at the pun-indian convention, punderously punned his way, punishing with punache and punch, the puny pundits, who punitatively expunged, his need to punder to his punny instincts