Write an intensely explicit pornographic "female muscle fetish" femdom story about NAME_1 a shy, skinny teenage boy losing his virginity to his beautiful, aggressive, dominant, musclebound, 6 foot 5 inch tall girlfriend NAME_2. Describes how she tears his clothes off, throws him onto the bed, then straddles him with her massive thighs and rides him hard until she climaxes with a roar, soaking him with her juices. Write vivid detailed description of NAME_2's gigantic muscles and breasts and contrast them with her beautiful, innocent, blonde-haired, blue-eyed angelic looks and focus on how small and vulnerable NAME_1 feels.