IRONIC WHIMSY

i·ron·ic (/īˈränik/):
Adjective:   1.Using or characterized by irony.

                  2.Happening in the opposite way to what is expected, thus typically causing wry amusement.

Synonyms: ironical - derisive - quizzical

whim·sy(/ˈ(h)wimzē/):
Noun:        1.Playfully quaint or fanciful behavior or humor.

                 2.A whim.

Synonyms: whim - caprice - fancy - vagary - fad - whimsey