He pulls down his pants

Jack stood, confused, not even sure what to say. The young man just took Jack’s hands in his own, lifted them off of his shoulders so that he could turn around, and set them back down. Then he hooked his thumbs around the waist of his jeans and in one motion slid them down and arched his back so as Jack looked down he saw the boy wasn't wearing any underwear. Jack was stunned, his thoughts still racing to catch up. Dumbly, he finally shook his head to clear his thoughts and just said,

“Your... your what?”

“Look at it.”

Jack was sure any moment he’d wake up, but what a peculiar dream. What was happening? His face wrinkled in perplexion, Jack shrugged and looked down, as the boy asked.

He couldn't really see much more than the cleft of the boy’s ass. Briefly he considered why he even cared, why he was actually doing as the boy asked, but before he could follow that chain of logic very far, he knelt down to get a closer look.

As the boy arched his back, his cheeks parted and Jack, moving like a man underwater, slowly saw the smooth skin of the boy’s crack as the cheeks peeled apart. Just as he knelt fully into a squat, Jack saw, nestled deep between the boy’s pudgy ass-cheeks, his wrinkled, brown anus, pulsing as the boy clenched and unclenched his sphincter.

Jack furrowed his brow, as if intrigued, as if trying to get a better look. He was entranced. He’d never really seen another guy’s asshole, and for some reason he found it fascinating. Looking at the change in skin tone as it approached the boy’s hole, seeing how the pucker wrinkled up and squeezed together when the boy clenched, seeing the creamy smoothness of the kid’s ass-cheeks, Jack just knelt and stared dumbly like a man looking at one of the wonders of the world, head cocked to the side a bit, brow furrowed in concentration.

Finally, Jack’s concentration was broken as the boy twisted to turn and look down at Jack kneeling on the ground behind him, staring down over his shoulder. Jack turned his head up to meet the boy’s gaze.

-Thread by AgainstMyWill