Seeking the title of a late-70's California teen beach sex comedy...

...featuring a scene where one of the "teen" girls with glasses hooks up with a midget surfer right on the beach and in a cabana or the like. I saw it once or twice on cable when I was a teen in the early 80's and actually found it online about a dozen years ago but forgot the title of it again. I recently met someone who claims that her aunt or second cousin was in such a movie and she can't remember the title either, but she said the description sounds familiar. It is rather unique and the woman in question could be a ringer for the actress in the movie.