Taiwanese phrase: Pretence of diffidence when you really can’t help yourself -「愛甲給細二」/「愛食假細膩」 ài chia̍h ké sè-jī

Greed,_1924,_06_banchetto
I was talking to my friend when he started talking about the vibe in Taipei bars, in the sense that people always complain about them every week, but still end up there anyway, due to fear of missing out. He said the following:
每周都出現在同樣夜店的人 嘴中總是掛著"I hate this place" “so boring here”但還是每周都出現,「愛甲給細二」。
(The people who turn up at the nightclubs every week are always saying “I hate this place” and “It’s so boring here”, but every week they turn up, they pretend diffidence, but they love it really despite themselves.)
The Taiwanese phrase he uses 「愛甲給細二」 is likely 「愛食假細膩」 ài chia̍h  sè-jī. This is equivalent 「貪吃假裝客氣」 in Mandarin, so “people who love to eat, pretending to be polite about it”.
There is also an alternate phrase with the same meaning in Taiwanese, which is pointed out at the Taiwan Language blog:
「iau(夭)鬼假細膩」  iau-kúi  sè-lī  which translates as “a glutton pretending to be polite”.
 Photo from Greed (1924) – Public Domain