cannot afford to; must not; impossible to do (for some reason)
Expresses that the speaker cannot do something because of social obligation, personal principles, or circumstances, even if they might want to. Often used with a verb in the dictionary form before わけにはいかない.
I have an exam tomorrow, so I can't afford to be playing around.
約束したからには、やめるわけにはいきません。
Since I promised, I can't just quit.