I saw a film on TV in color, of at least 10 years ago. Set in a place that looked like England, but i’m not sure. It was narrated in first person. The plot was of this boy (20ish) pressured from the parents into a catholic education who got a job either as a postman or a paperboy: It had a dark and serious tone. While he’s delivering to a house it starts to rain hard, the girl he’s delivering to (of roughly the same age) lets him and feeling “sorry” for him asks to remove his clothing and set it next to the fireplace. He finds himself nude in front of the fireplace holding his genitals. After a bit of talking they get closer and eventually start having sex. Meanwhile the protagonist narrates his thoughts that summed up say “Who gives a shit about christianity, this is exciting and it is my first time” faster and faster as he removes her clothing. Nothing is shown on screen, even if the plot looks like something from a porno, the tone was serious and realistic.