Just Looking (1999) on Netflix

Plot summary

Lenny Levine is fourteen and lives in the Bronx in 1955. He is fascinated by sex, but he is too young and too scared to do it himself, so he sets his summer goal at watching two adults in an act of love. Caught spying, he is packed off by his mother Sylvia and his stepfather to Queens, where his aunt and uncle take him in. There he falls in with local teenagers who run what they call a sex club; they only talk about sex, but they know more about it than anyone he knew at home. He also meets Hedy Coletti, a nurse about twice his age who once modeled for bra ads, and his interest in her pushes his plan further.