slippery slope

an idea or course of action which will lead to something unacceptable, wrong, or disastrous

會導(dǎo)致錯誤（或?yàn)?zāi)難）（或會遭拒）的觀點(diǎn)（或行為）

he is on the slippery slope towards a life of crime.

他正在滑向罪惡人生。