Everything You Wanted to Know About Sex...But Couldn't Pronounce

S3, E20: America's "heartthrob," Keith Partridge, is failing his sex education course at school. When the family hears about this they find it hard to stifle their laughter, until they realize that if he does fail, he won't graduate. He can make it up in summer school, but that would mean canceling the Partridge Family summer tour, their biggest yet. When Shirley tries to find out why Keith is failing, Keith tells her it must be because Mr. Grisbee, his teacher, doesn't like him. He feels his work is better than that of others in his class, but he gets lower grades. Shirley goes to the school to talk to Mr. Grisbee and learn if he really is being unfair to Keith, but Mr. Grisbee is in a rush and curtly dismisses her. Keith decides that he will get an 'A' on the final exam and make it impossible for Grisbee to fail him. He studies night and day, getting very little sleep. The day of the test he goes to school early to get in every minute of studying possible. He falls asleep under a tree and misses the test. After convincing Mr. Grisbee to let him make up the test and taking it, Keith is sure he failed it when the teacher asks him and Shirley to come up to school. Grisbee announces that Keith got an 'A' on the exam, and the reason he had been so hard on Keith was because he did not feel Keith was doing as well as he could. He had done just enough work to get by with, but had proved by passing the final that if he really tried he could be an excellent student.