Excuse my French

Taking advantage of the current location of some of my students of 4ºESO, this week's idiom deals with a neighbour country. 

Ok, so here it goes... I think you all going to like it.

Excuse/ Pardon my French

Let me show you some pictures so you can deduce its meaning.

And another one:

And finally an example with context: 

” If you’ll pardon my French, but I think you’re a %^&*!”

And here's the definition:

In the days when language propriety was more of an issue than it is now, using a word or phrase that was “unfit for mixed company” was likely to lead to   embarrassment. Since French was considered a racy language, people excused      themselves with “pardon my French.”