[***facetious*** (Oxford Dictionaries):][1]

>*treating serious issues with deliberately inappropriate humour; flippant*

I'm looking for a word that means the total opposite; to treat humorus or non-serious issues with deliberately inappropriate gravity. There exist a few words and phrases that can get the idea across (cantankerous, old grouch, stick-in-the-mud), but they usually speak to more than just my specific sought definition. Also just a word would be preferable; phrases generally aren't nearly as satisfying in their delivery. Thanks.


  [1]: http://www.oxforddictionaries.com/definition/english/facetious