immoral, unorthox or simply natural?

When I was a kid, there was a TV series I used to watch. In one episode, a man who was in jail, was released and his family was waiting for him outside the blocked walls. When he came out, I expected him to go to his wife and kiss her, just as my dad did when he came back from a trip. To my great surprise, the man stood in front of her, said hi, looked at her and started talking to her. I couldn't keep silent and shouted: "Hey why don't you kiss your wife? You haven't kissed for a year! ". My dad said, while a bit in a temper: "how mindless they are! If you don't want to show an inevitable intimate scene, just turn the darn camera to the other man who only has his brother waiting for him to come out of jail, or just change the damn scenario"

Later, I noticed at airport, couples who met after separation, or were about to part,  didn't kiss on lips the way they should. If a kiss lasted a bit long, people's head turned towards them.

Is this act immoral? No, I thought, but it surely was unorthodox. Later, when I went to Lebanon, I realized that people do not French kiss in public but are way more relax than in Iran. I didn't know what I could relate this to; was it due to being a Muslim country or to its being underdeveloped, as it's called.

So I kept my eyes open when I went to Ghana, a relatively poor and underdeveloped country compared to the former 2. I was amazed how relaxed people's intimate interaction was. I told myself, so it definitely has to do with being a Muslim country.

In Europe though, these interactions are way more relaxed and you see people kissing each other in public, on a daily basis and no one goggles at them.

Last weak, while I was walking on the banks of Seine with a friend, I saw this couple and I stopped to shoot them.  Suddenly, the girl realized and I immediately went to her  and while showing her and her boyfriend the photo, told them that if they didn't like it, I could delete it but they were ok.

Actually this made me realize they were Arabs and most likely Muslims. I put on my thinking cap and I told myself: these people are in Paris where kissing in public doesn't make them nonconformist, yet they still do it covertly. Could there be other reasons than thinking of it as a very private act which would seem immoral if done in public?