Probably saw this between 5 and 10 years ago on TV

English language, set in US

I was only barely watching this when it was on but for some reason can’t get it out of my mind. It’s a movie following the lives of a group of wealthy, young people, and appeared to have themes of hedonism and self destruction, quite dark undertones.

I can only remember 2 scenes clearly:

A girl is relaxing on a beach but appears to be very weak or ill or something. She is talking in a kind of dreamy carefree way with a guy who is with her, and her speech tails off as if she is sleeping, but from the way the scene is filmed it is implied that she has just died peacefully there and then (or at least that’s how I remember it).

There are lots of sex/drugs scenes, including one where a group of people are having an orgy in a dimly lit, opulent room with large sculptures. The camera follows a bystander who looks on at the activities but is hesitant to get involved for some reason.