I just remember few details, but the title of this movies, anybody help give me some suggestions??

You do or don't remember the title? What is it about?

This movies is about a beautiful woman coming to visit a family and a young man. May be she is his grandma's sister or sort of relatives. There are some sensitive situations in this movies, like she asked him to get her shampoo while she was naked in bathroom. Finally, they had sex at night just before the day she flew back home. I don't remember the title and the movie's from 1980's. Help me find it out!