One might say and/or think that strokes is quite the innuendo here. And if you watch the explicit cut of the movie (there is a softer version available of this), you would be excused for calling it a pun. Having said all that, this is quite the family. If you try to be open minded (if you aren't already or maybe your family is close to this anyway), you will get a story of how (not) to raise your kids. And how to grow up, how to communicate ... actually as this is one example of how things can go down, you can imagine that this is not a blueprint. Nor for or against anything shown here.
As said, some might want to try the softer version, if you don't want to see certain things. Funnily enough both versions are rated 16 in Germany. Which I guess says something about how sex is being seen and appreciated (or marginalized). Again it is always a matter of perspective and how you have grown up, what you have been taught. So don't blame the movie for certain things it depicts or the fact that almost everyone is beautiful (although I've been told I'm too nice in certain regards, so you may have other beauty values yourself). French cinema over the last decades has gone nude ... not all of it, but they seem to like the theme and they don't shy away - provoking much? Maybe, but there comes a point (no pun intended), where it is almost normal, yes? Is that good or bad? Who am I to judge?