cut sb. some slack这句习语来源于船舶的停靠，引申为给某人方便，对某人网开一面。

【例句】
Cut her some slack.She just had a baby.
对她网开一面吧。她刚生小孩。

I know you've been through a lot, so I'm willing to cut you some slack here. But, don't you yell at me again, okay? Enough is enough.
我知道你最近不好受，所以我愿意放你一马。但是，以后别再对着我大吼大叫了！适可而止，别太过分。