This is not a laughing matter but a cause of big concern.

这是我们需要严肃对待的，应该引起我们的关注。

youdao

In one case a child was followed. Whether those involved are doing it for a joke or not, this is no laughing matter.

在一次案件中，一个孩子被尾随。不论这些人是否在开玩笑，这一点都不好笑。

youdao

It's not a matter of laughing.

这可不是开玩笑的事情。

youdao

And that's not a laughing matter, no matter how alien that makes me feel in my own home country.

CNN: GOP House's inaction on VAWA shows bigotry

For the Tartan Army who did not join the 500 footsoldiers in leaving the stadium after Wales' second, it was far from a laughing matter.

BBC: Storm clouds gather over Scots