不忍心

不忍心	bù rěn xīn	can't bear to (do sth emotionally painful)
不	bù	no; not so / (bound form) not; un-
不忍	bù rěn	cannot bear to
忍	rěn	to bear / to endure / to tolerate / to restrain oneself
忍心	rěn xīn	to have the heart to do sth / to steel oneself to a task
心	xīn	heart / mind / intention / center / core / CL:颗,个