looking for a movie

[mpelos]

i can only describe a scene since i remember not much

there is the son going down to a beach with his mother
the stay there for a while and then they move back to their house
there something happens to the mother and she kind of passes out
then the son takes the opportunity and starts having sex with her
after she wakes up they go to the bed and continue the action

if anyone has any idea which movie this is please let me know

thanks