Hard Scandal: Sex Drifter(1980)

A junior high school student spends his nights hanging out at the disco. At home his parents are more interested in swapping partners with willing couples than spending time with their son. One evening, while shoplifting, a young woman gives him a hand and helps him pull off the snatch. Mesmerized by the woman he follows her to where she lives. After he makes a fumbled attempt at raping her she lets him stay and they spend a lazy summer together.