うっかり (translations)→ absentmindedly accident accidentally careless carelessly fear heedlessly inadvertent injudiciously let nearly thoughtlessly uncertainly unguardedly unintentional unthinkingly venture
うっかりして (translations)→ absently silly
つい (translations)→ actually always automatically but day easily hard involuntarily involuntary just keep mere only quite simply slightly sometimes tend typically unintentionally unwisely very
なにげなく (translations)→ indifferently innocently lightly
ふと (translations)→ abruptly accidental briefly chance dare instantly momentary soon sudden suddenly unbidden unexpectedly when
思わず (translations)→ impulsively instinctively unconsciously unwillingly visibly
心ならずも (translations)→ inescapably regretful reluctant reluctantly unwanted