Birds and bees, birds and boys--I didn't know what to think about first,"" says narrator Marilyn, 11 and in seventh grade. Her club, the Four Roses, is working on a science-fair project that involves her pet quails hatching their first eggs; meanwhile, classmate Robby--precociously sexy and full of innuendos--is coming on strong, and also flaunting his exploits with big-breasted bad girl Holly, who wants to join the club. The Four Roses--who are unusually earnest, ""good"" girls--are nonplussed when Robby turns their club party into a kissing-game fiasco. But when one of Marilyn's birds is injured, it turns out that there's more to him, and to Holly, than Marilyn had imagined. The plot here hinges on some stereotypical notions, notably that girls who develop early are loose. On the other hand, boys like Robby, whose charm and single-mindedness about sex fascinate their contemporaries, are more apt to occur in real life than in fiction. An interesting theme, if not memorably presented.