Translation of obligatorisch

This website helped me learn French. Although most of the users intend to learn either Spanish, German and English some users come here to learn French. I met a few people that helped me with it.
The short story 'Hills like white elephants' is a short story about a relationship between a man and a young girl, based on having sexual encounters. The meaning of this story is not immediately recognizable.
At around eight in the evening we were back, took a hot shower and met our friends for a fancy dinner. They were leaving the country the next day and we would stay there another three days.