This is a frequent misspelling of the correct chengyu
不能自已 (bùnéngzìyǐ — 'unable to stop oneself'). The correct character is
已 (yǐ — 'to stop, already'), not
己 (jǐ — 'oneself'). Even native speakers confuse the two because the characters look almost identical and
自 +
己 ('self') seems to make sense. In careful writing, always use
不能自已.