Translation of disingenuous in German

My mom and dad used to speak English when they wanted to say something I shouldn't understand. In this way I have learned English. I did not tell them till late, but I did understand every word they said.
We will soon improve our page about language schools, cause we believe that learning with other students in other countries is a great a experience that you will never forget and it helps your language skills.
I was one time in Jerusalem and in Tel Aviv! Fantastic two cities. I liked Tel Aviv, and I want to get back soon. I want also to visit more cities around the globe, especially in East Asia.