not recognizing one's family (idiom); self-centered and not making any allowances for the needs of one's relatives
Definitions (粵典–words.hk)
語句
形容人不留情面、反面唔認人,甚至連自己嘅親人都扮唔識 to refuse to recognize one's family and close relatives; to be heartless
佢發咗達之後就六親不認,睇唔起我哋啲窮親戚。
佢发咗达之后就六亲不认,睇唔起我哋啲穷亲戚。
keoi5 faat3 zo2 daat6 zi1 hau6 zau6 luk6 can1 bat1 jing6, tai2 m4 hei2 ngo5 dei6 di1 kung4 can1 cik1. Since he became rich, he refused to recognize his family and looked down upon the poor relatives like us.
Definitions (Wiktionary)
phrase, idiomatic
to not recognise any of one's relatives