ついつい

ついついtsuitsui

adverb

  1. unintentionally
  2. unconsciously
  3. by mistake
  4. heedlessly
  5. against one's better judgement (judgment)

Study it in Yanamino

Data from JMdict, KANJIDIC2 (EDRDG), KanjiVG, CC-CEDICT and Make Me a Hanzi. Sources and licences