Keith Partridge is the lead singer in a rock band, which sounds cool. Except that most of the other members are little kids. And, oh, yes, his mom. Steamed by the restrictions this places on his attempts to be a rock star, he goes into his mom's bedroom to confront her. Surprised but aroused by what he sees, he takes matters into his own hands. She is initially upset but eventually decides it wouldn't be a bad idea to get to know her son in the Biblical sense.
When important Adam returns home early, he finds his wife and son doing what no mother and sone should be doing. His daughter, Jody, was also secretly recording them from her bedroom window. Soon shock turns into something much better