I would start with the fact that the people of Islamabad are quite liberal if you compare them with the rest of the Pakistan. Most the population is educated and a lot of them can speak English fluently. Many have accepted the western ideas. Girls specially talk with a made up American accent.
Let me now tell you about the atmosphere in my school. Most of the students that study in my school can be presumed to be belonging to the upper middleclass rather than the elite class of citizens. A large percentage of boys and girls would mingle with each other and converse quite freely on various subjects.Boyfriends and girlfriends are quite common. Students try to be more trendy and fashionable to gain popularity and attract others attention.Music is a popular topic the teenagers here. Most have the latest information about the western music scene. Boy are particularly influenced by the rock music and the hip-hop culture. A lot of people in school can afford latest gadgets like expensive mobile phones. Portable mp3 players are quiet common and their head phones can be seen clanged to their ears.Some even own cars. So the environment here can be associated to a western high school (except that we don't have lockers here).
I am explaining this due to the fact that Islamabad is quite different for the rest of the cities of Pakistan.Activities that happen in Islamabad do not happen in other cities except for bigger cities like lahore and Karachi. Unlike the other cities Islamabad is quite liberal.Although I would say that we as a nation are losing our identity and culture.