A year had passed since the two siblings had taken each other as mates. They and their mother and his two daughters now lived in a remote cabin far from prying neighbors. The little ones were growing at an accelerated rate and though they were only one year old, they appeared more like four year olds. His mother told him he would have to breed them soon or they would die, just like his sister would have. He was wanting to fuck their cute little bodies for fun but his real love was his sister. He could think of nothing but her screaming on his dick, taking him in and pumping him dry.
She had not conceived since her first-born, and he believed it was because he was holding back the sperm from his semen. Tonight, it was time to implant a son into her. One who could save his sisters.
"Sis," he said to her "we need to make a son to mate our daughters"
"But I thought you were going to screw them?" she seemed concerned for him.
"Oh I will, just to feel their little tender meat rip as I awaken their abilities, but I can't imagine loving any other woman as I do you"
He watched her tremble then suddenly she ran to him. He lifted her and carried her to their cot. She wrapped her legs around him as he sat, his ready cock in position in her slit. They locked lips and sucked at each others toungues and lips, saliva flowing between them like sweet wine. He oozed precum and lowered her onto his staff. Once his tip entered her vagina she squirted on him and he let her weight slide her home. She had released her legs, abandoning her young womanhood to his unforgiving pole. He no longer ripped her apart when they had sex. Her body had adapted and while he missed the feeling of power over her it gave him, she was able instead to drive him crazy with incredible orgasms, squeezing out his cum into her.
Her belly was bulging under her rib-cage and he still had the urge to penetrate her in a bloody manner. Inside her, her guts writhed up and down him, making him fight to hold out. He grabbed her back with both hands and held her tight as he ground into her slow and deep. He thought ,"Finally, time to let the boys swim free" and as he allowed his sperm to release, he climaxed as if it was his first time. They tried to continue their kiss as their lips numbed, but they both jerked back as if losing their breath. He roared and she arched back grabbing her tiny breasts, presenting them toward him. He saw her nipples and in his lust he pulled her to his mouth and bit down on her one breast. Her shriek was exciting in his ears and he chewed and swallowed nipple flesh and gland. She sobbed with the pain of it. But when he had eaten his fill, he held her gently and stroked in her rapidly to get their shared orgasm.
After, she lay on him as her breast grew back. She was no longer flat-chested, and she was pregnant. He could sense the child in her. Meanwhile his belly burned from her devoured breast. He wanted to taste more...