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