have one's heart in one's mouth
提心吊胆
A：I don't date to look after the children now.
A:我现在不敢照看小孩了。
B:Why?
B：为什么?
A:The children always make themselves in danger. I always have my heart in my mouth with them.
A:孩子们总是使他们自己处于危险之中，和他们在一起，我总是提心吊胆的。
B:It's because your children have grown up. and you haven't lived with a child for a long time.
B：也许是因为你的孩子已长大了，你很长时间没有和小孩在一起生活了的缘故吧!