I watched a movie between 5 and 10 years ago on TV about a girl, I believe she was a teenager and a waitress. I remember that she develops feelings for an older, married man, I remember him being a teacher of some kind. He has a telescope at his home so he may have been an astronomy professor. I remember at some point the main character goes to his house to look through the telescope and his wife is away. I think they at least kissed.
Something I remember best is that one of her friends was a nymphomaniac. There is a scene where this girl and her boyfriend enter the boyfriend’s house, it’s at night so all the lights are off. They are kissing and she wants to have sex in the dining room or the entrance room of the house. The boyfriend isn’t too keen. I think they are interrupted by on of the parents shouting.
I remember vaguely a scene with the nymphomaniac and a bunch of friends on a boat or yacht.
That’s all I can remember.