1.Our relationship is strictly platonic.

我们的关系很纯洁。

2.We fell out.

我们闹翻了。

3.There's no need to sustain this relationship.

没必要继续交往了。

4.You can confide in her.

你可以完全信任她。

5.That's life.

生活就是这样。

6.This is the life!
这才叫生活!

7.She's been leading him on.

她一直牵着他的鼻子走。

8.All my hard work is nullified.

我全部的心血都泡汤了。

9.He revealed it in an unguarded moment.

他一不小心说漏了。

10.Don't cast pearls before swine.

不要对牛弹琴。