It's a sex comedy; the efforts of high school students (actors in early to late 20s) to end their virginity comprise most of the plot. Minor attention is also paid to teen pregnancy and to STDs and safe sex.
There's one quick glimpse of breasts at a party. A movie sex scene is projected in class with a man and a woman lying down for sex; side of breast and butts is visible. Girls are seen in bras a few times.
People intrude on a man and woman lying on a bed in a hotel room, interrupted sex is implied but not seen; no nudity.
In sex ed class, a full screen, detailed, educational drawing of a penis in flaccid and erect condition are viewed. A statue has breasts visible for a while.
Discussions about sex are pervasive but rarely vulgar. By contrast, there is a near (possibly complete) absence of sexual assault or coercion.