I'm trying to remember about the name of this movie that a couple of brothers were sent with a old couple to live with them. The old couple lives rite in front of the beach. One of the older boys meets a girl, she has came to that place over the summer. They start having sex in a cave near the big rocks on top of the beach. Later he founds out she left and did not really liked him, but was used for sex. The girl and him smoke as well as drink alcohol in there "relaxing" place.

December Boys (http://en.wikipedia.org/wiki/December_Boys)