Megan was out on her morning jog when she saw Jen and her parent's grow and transform right before her eyes. Megan was mesmerized by the impossible sight before her. She began to wonder how they felt, being so massive, so sexualized. Soon the scent of roast chicken began to fill her senses as Jen's pheromones washed over her and began to answer her curiosity, in a fashion.
Her toned thighs surged with both muscle and fat, tearing both her jogging pants and underwear to shreds. Her height began to climb rapidly as her legs grew upwards as well, leaving her upper body completely untouched. Dry, black scales coated her ankles, already as thick around as a tire, and her toes merged into four bird talons. Pinpricks ran down her arms, slowly sprouting into black feathers that covered her arms and simplifying hands. By this point her thighs were thick enough that the entire floor plan of one of the houses at her feet would fit inside them, not that she could see any of the houses near her anymore, as her vision anywhere but straight ahead was dominated by the meters of hips and ass that surrounded her still normal sized upper body.
The final change to come over her was a growth between her twenty-five meter tall bird legs. At first she thought this growth was another leg, the general shape was right and she didn't immediately think of anything else it could be, but the incredible pleasure created by the friction between it and her thighs made her second guess that idea. Each time this new addition throbbed larger, Megan found her mind clouding deeper with a lustful fog stronger than any runner's high she had experienced. Eventually the new addition grew big enough to free itself from the confines of her legs. The mushroom-shaped tip connected to a veiny shaft left that flopped up in front of her left no doubt that Megan now had a ten meter long—and still growing—cock between her legs.
The release of Megan's cock didn't completely alleviate the pressure between her legs however, as she had also grown an equally massive ball sack that soon squeezed out from the back of her legs. This massive sack was stuffed full with six gonads that slapped heavily against the back of her thighs, the lowest point nearly touching her knees. Now freed from their fleshy prison these balls all began pumping their seed up through their owners thirty meter cock, launching it so far that it flew clear over the heads of the three giants who started this clear to the next town over.
Despite her incredible orgasm, Megan barely felt satisfied. Her cock was still painfully erect, its length stretching out across her view, and her balls were already overfilled with more cum. With no other recourse the mega-legged harpy began walking towards Jen and her parents—careful not to step on any of the transforming people beneath her—as they were the only people anywhere near big enough to satisfy her cock.