This is as best as I remember and some details might not be accurate. A boy is in love with an older woman. She is an actress. He writes her a letter and she invites him to her house. He bumps on something and she gets angry saying "I invited you off the goodness of my heart". Then gives him a glass of milk. At the time, an old classmate finds him at an adult entertainment store. They walk and she gets into a bus. She asks him if he remember her. He barely does and says "you were so ugly". He brings suitcases and moves in with the actress. The relationship doesn't go well and he lives several times. At the end he realizes she is been playing with him and has a romantic relationship with his old schoolmate. The movie ends with them running on the street with cars, kissing and laughing.

The movie is You are a "Big Boy Now" 1966 Peter Kastner and Elizabeth Hartman. Great movie.