The stallion watched her move around, well coated and slick as his member was. She had the fire burning and was trying to reconcile any way to put it out, even this rather interesting suggestion. His eyes widened slightly as she presented herself, and made it clear what her intensions were. He was not one to argue. Like a good little horse, he stepped up behind her and took a hold of his member with one hand, pressing the tip against her puckered hole. It was far tighter than the poor little Mesa had been, and it caused him to spurt precum inside of her. With a grunt and a snort, the flared tip popped into her, fairly well locked as it gripped his shaft. She would have to endure as his hands took hold of her hips, pushing forward slowly, curious to see how far it might go into the human.