Strange, alien pressure. Low in his belly, overwhelming and hot, then burning up forward, tilting to the left and burning up up up, lighting fire in his tummy and then down in his hole, opening widening bearing burning. Sirius finally screamed, choking on sobs and begging his Daddy for something he needed, “’s too m-m—” and he needed it bad, yet he couldn’t even find a way to move his arms, he couldn’t close his legs
The fullness moved inside him, swirled and pulled at his focus. It tugged him deeper into the fog, into the clenching and the begging, and the crying and the wailing, “m-my—” he said, over and over and over, yet Daddy just laughed again, and pushed himself deeper, until his small tip bumped against the end of Sirius.
But Daddy’s fingers crawled over the smooth skin of his belly, then his palm rubbed and pushed and Sirius gasped as he once again opened in a way he wasn’t supposed to, and Daddy moved forward, more and more and more until the fire in Sirius’ crotch exploded and he was swallowed by the flames, convulsing so hard that the funny chair made tinkling noises like a fairy.