i'will not tolerate rude behavior at the expense of a i'will not tolerate rude behavior at the expense of a fellow,这句话中的expense什么意思?为什么会用到这?

i'will not tolerate rude behavior at the expense of a
i'will not tolerate rude behavior at the expense of a fellow,这句话中的expense什么意思?为什么会用到这?

at the expense of 短语,以.为代价.