There are a few sequences of implied sex. In these, the film goes through a montage of kisses during a musical interlude, or there is an evening/morning sequence. These are sometimes heterosexual and sometimes not.
In one scene for example, one college boy hires a stripper to spend the night with a college acquaintance so that he can lose his virginity. There is a montage of the stripper doing a lap-dance followed by the beneficiary thanking his (now) buddy for arranging the evening.
The nudity is limited to a couple of shots of breasts.
There is also discussion of gay life that includes very succinct but explicit descriptions of some fairly commonplace sex acts.