This is one of the edgy late episodes of the series. I've always found this one difficult to watch because of the bone-headed behavior exhibited by Beaver. Nevertheless, it's a good cautionary tale about honesty in relationships with the opposite sex.
We open with the Cleavers at dinner. The telephone rings, and June goes to answer it. It's a girl, she says; and Wally gets up, all ready for action. But no, she says; it's for Beaver! ("Me?!" Beaver asks incredulously, with just the right adolescent squeak.) It's schoolmate Peggy McIntosh (played by Veronica Cartwright, who was previously cast in the series as Violet Rutherford), and she is asking Beaver if he wants to take her to the graduation dance. Beaver is purposely vague in his answer to Peggy because, as he puts it, "You have to keep girls guessing." Ward admits this method has "certain advantages under certain circumstances," but June thinks it's "mean" and demands that Beaver call Peggy back and give her an affirmative answer, which Beaver does next day at school. Peggy is pleased, and everything is peachy.
Oh, but this paradise couldn't last. There's a seductress winding her way through this Garden of Eden. Her name is Melinda Neilson, and she's a junior southern belle from Charleston, South Carolina. She's new in school, and when all the guys aren't clamoring to give her directions to the various rooms, they're standing there gaping at her. Beaver is smitten too. That night when Peggy calls Beaver up to invite him to the dance, Beaver is faced with a dilemma. He wants to break his date with squeaky-clean Peggy to make one with sultry Melinda. His parents call this out for the dishonorable deed it is.
Speak of the devil, in walks Eddie Haskell, who knows every deceitful trick in the book. His advice for Beaver: get Peggy to break the date by doing things to annoy her. Beaver proceeds to do just this. Without spoiling any more of the plot, suffice it to say Beaver gets what he deserves in the end. Yet we also sense that he is happy finally to be free from all entanglements with the fair sex.
This is a prime example of how the last-season plots of LITB often approached adult complexity and importance. Who would have thought cute little Beaver would turn into a Don Juan? How many adults have gotten themselves into situations like the one Beaver gets himself into here?