When Phyllis falls in love with the shepherd Strephon, she doesn't know that he is the product of a marriage between a mortal and a fairy. So when she sees him embracing the apparently young and undeniably attractive Iolanthe, Phyllis naturally refuses to believe his assurances that the lady in question is actually his mother, and gets her own back by becoming engaged to not one but two peers of the realm. Whereupon Strephon does what any self-respecting shepherd lad would do under the circumstances: he goes into Parliament--with hilarious consequences.