我讲这话不是开玩笑的。

I'm not saying it in fun.

《新英汉大辞典》

而且我也知道你不是开玩笑的。

And I see that you weren't joking.

youdao

我要纠正一下，不是开玩笑的。

That's a correction, no kidding.

youdao

So this one is not a spoof, it's actually a pretty cute video and it offers us the opportunity to just take a look at some of the kinds of ideas we'll be looking at in this course.

这个就不是开玩笑了，它其实是个比较有趣的视频,它让我们有机会了解,在我们课堂上会讲到的一些思想。

哈佛公开课 - 计算机科学课程节选

That seems like a bad joke,but if the body theory is right, it's not a joke at all.

又是一个冷笑话，但如果肉体主义者是对的，这就不是开玩笑了。

耶鲁公开课 - 死亡课程节选

No kidding, where is this?

我不是在开玩笑,你在哪认识他的

耶鲁公开课 - 古希腊历史简介课程节选