"ça se fait pas", it is a phrase I often hear during conversations, which for me means "we don't do this". It touches the things that French won't normally do / ask, but they are more tolerated in other cultures. Since I'm a foreigner, I sometimes take advantage of the situation, by simply pretending that I don't know that it is not a common practice in France, and would go ahead to do it.
We went to a restaurant with grandmas and there were plenty of leftover. I suggested that we asked for a doggy bag, and the grandmas told me that "ça se fait pas en France" (we don't do this in France). After some thought I decided to ask anyway, the worst was that I get a "no" in answer, or I could take home the leftover and not waste the food. The result : they got me a doggy bag, the grandmas were surprised.
Recently we were invited to a birthday celebration. We asked around if someone would collect money to buy a common gift, but we were told that we would contribute financially as they were inviting a band to play traditional musics so that guests could dance. We had a great time.
The second morning, after greeting each other, the first thing I asked was how much did the band cost and if they managed to collect enough money to pay the band. I got an answer, but I was told later that "ça se fait pas", basically topics involving money are mostly taboo in France. I would know a French for long time and we are good friend, but we won't tell each other how much we earn (I'm willing to tell but I think it would make people uncomfortable because they would feel oblige to tell me theirs). Whereas money (how much you earn, how much you paid for your house, your car.... ) are something so commonly asked by the Chinese, even by those living in France, and during the first encounter.
When I go to Asian restaurants, and if I know the chef well, I would ask for things like changing to another table, asking to switch a dish I like that is à la carte to be included in the menu of the day. Hubby told me you don't do this in French restaurants, he was amazed to see how we always negotiate with the waitress / chef.
So over the years I get a lot of "ça se fait pas" comments on what I did, sometimes I respect and follow it because I was convinced of the reasons, but sometimes I just don't care or old habit dies hard the question just came out naturally. So far nobody got offended, or they were but they didn't show it.
On the other hand, there are things that the French do that the foreigners would think "mais ça se fait pas!" (but we don't do this!).
People on strike or on demonstration publicly destroying shops / blocking highways & public transports / burning cars.... We have many recently : demonstration against building an airport (the talk of building this airport was started like 40 years ago), demonstration on the new labor laws, farmers' demonstration due to falling livestocks prices. It was always a shock for me to see how much things got destroyed after each demonstration, and how the police were just there watching, and people in general tolerated these behaviors. I read in an article, the unions argued that having demonstrations and sometimes destroying stuffs is the fundamental right of each French people. Destroying, is just a way of expression, and that's in the French cultures. Ok these might only be the point of views of certain unions, but in general, French people just give a shrug of shoulder towards these behaviors.
When the season changes the flu virus has gone viral. People clearning their nose openly in public, in the office, that still amazes me.
French men, when they need, just stop their car in the middle of highway, and pee.
I have no word for this.