The stable had to be quarantined for a couple of days until Amy's heat dissipated, with stable hands wearing special masks carrying exhausted demons and horses away and bringing fresh horses to keep Amy well tended throughout her rut. Even the breeder demon had to be dragged away eventually. The situation was managed by Carl, who rewarded the breeder's heroic efforts by sending the farmer's daughters he'd corrupted to nurse him back to full strength. It didn't take long with six tits to draw replenishing tainted milk from and he left them all with demonic hellspawn in their bellies before charging back into the fray.
When it was over, Carl entered the stables and tossed his dildo into the lake of cum that surrounded his mother. She was suckling on one of her now much larger tits when she noticed him.
'Hello dear,' she said. 'Thanks to the gangbang bender you helped maintain I now seem to lactate cum. Care to try?' She offered her other breast to him and he approached without any care for the jizz of several stallions coating her skin. Between Corey and the dildo such petty matters of sexuality had been driven from him completely.
'You are quite right, Mother. Equus will be pleased.'
'Indeed. Especially once the demon growing inside me is spawned from my loins. I doubt that it'll be much more than a day or two.'
'Excellent. I shall fetch him with this news at once.'
When Carl returns with you, you are indeed pleased. The sight of your favourite human-mare in such a state of depravity is enough to make you stomp your hoof and add another layer of horsey-jism on the slut. She opens her mouth to receive your gift and gargles what she catches before swallowing with a sigh of pleasure.
'Tell me, my slut,' you say when she has finished her display of worship. 'What is it that grows inside you and the other mares?'