Several couples have sex inside their cars, or are generally intimate. Nothing is shown but you hear moaning etc, just legs poking out, visible (though one car has legs poking out over both sides, so that particular couple doesn't seem to understand the mechanics). It's strongly implied that many couples are having sex.

a woman touches herself in the bathtub, apparently for the very first time, after being told she can have fun without her husband. No nudity, we see her face as she moans, and as she climaxes a tree outside the house bursts into flames.

Multiple paintings of nude people are shown in an art book; also one male character paints a mural on his shop front of a female character, naked.

Many characters are completely unaware of what sex is, and their discovery of it is sometimes very humourous.

Extramarrital affairs (cheating)

In a group of teenage girls wearing white tops, one of the girl's nipples show through the top.

A girl says "I've worn some kinky stuff"

In a Museum window a mural show brief male shirtless nudity

Mild sexual reference . For example, there is a joke about "safe sex", on old TV, where two beds are separated by a bedside table. There are also several short scenes in which it is suggested that young couples are making out in cars.

A mob forms at the diner and a young man throws a rock through Mr. Johnson's full window painting. Another does the same, and then several men throw a park bench through the window. The mob then breaks into the diner and ransacks the place. Later, the mob also burns many books.

One boy punches another boy who was harassing a woman. He falls to the ground and has a bloody lip, which is especially visible because the blood is red and everything else in the scene is black-and-white.

5 mentions of the s word

2 uses of "goddamn", 11 uses of "oh my god,", seven uses of "oh god," one use of "I swear to god," one use of "god," one use of "Jesus Christ", one use of " holy cow"

1 use of fucked up, swear to god and other milder words.

2 uses of shit 5 uses of sex

A girl says she wishes she had a cigarette

Reese Witherspoon's character lights a cigarette, inhales and exhales one time and then gives it to her friend who holds, but not smokes, it while Reese's character chats with a boy.