He asks her to put on some clothes

Mason looked at her body. She looked incredibly attractive. His cock twitched under his shorts, starting to harden again even though he had just changed. The way her breasts hung there, full and soft, the curve of her waist into her wide hips, the smooth skin of her thighs, it was too much. He wanted to test how good her perfect ass would feel rubbing against his cock. He could already imagine telling her to turn around, bend over and press that round ass back against him while he stayed seated on the couch. The thought made his mouth go dry and his dick throb harder. He had to stop himself before the idea went any further.

“Go dress yourself,” he said quickly, trying to keep his voice steady. “Put on some clothes right now.”

Serena nodded once, still looking down. “Yes, Master. I will obey.” She turned and walked back toward the bedroom. Mason couldn’t help watching her ass as she left, the way it swayed with each step, firm and juicy from all her gym work. He **** himself to look away once she disappeared through the door.

He let out a long breath and rubbed his face with both hands. This was going to be harder than he thought. Every time she obeyed instantly it sent a rush through him. The submissive way she bowed her head, the calm “Yes, Master,” the complete lack of shame about being naked, it was messing with his head. He kept remembering how she had looked on the floor earlier, legs spread, fucking herself with his baseball bat. How she had mooed and pissed on the carpet without any hesitation. Now she was walking around like a living sex doll that only he could control. And the worst part was that some dark corner of his brain liked it. Liked it a lot.

Mason shook his head hard. No. He had to focus. He was going to save her, not use her. She was still his sister underneath all this programming. The girl who had protected him from their abusive mom, who had spoiled him with gifts and takeout when he felt alone, who had always made sure he never felt the full weight of their shitty childhood. He owed her more than this.

But the memory of her perfect tits soon involuntarily entered his mind again, something in Mason’s brain snapped. The image of her perfect ass swaying with each step burned into his mind. His cock was already rock hard in his own shorts, throbbing painfully. He sat there on the couch for a few seconds, breathing heavily, trying to fight it. Then the fantasy took over completely, flooding his head whether he wanted it to or not.

He imagined standing up quietly and following her into the bedroom without saying a word. Serena would be standing there by the bed, still completely naked because she hadn’t actually put her clothes on yet. Her long jet-black hair would be hanging down her back, still slightly damp. Her massive breasts would be hanging heavy, nipples stiff from the cool air in the apartment. That hourglass body, tiny waist flaring out into those wide hips and that thick, juicy ass, would be right there for the taking.

In his fantasy Mason wouldn’t say anything at first. He would just walk up behind her, grab her by the hips and shove her forward so she bent over the edge of his bed. Her massive tits would press down against the mattress, squishing outward. Her perfect round ass would stick up high, cheeks spread slightly, her tight little asshole and puffy pussy on full display.

“Master?” she would ask in that calm, obedient voice, but he wouldn’t answer. He would just pull his shorts down, free his aching cock and spit on his hand to slick it up. Then he would press the fat head of his dick right against her asshole and push in hard.

Serena would gasp, but she wouldn’t fight it. She couldn’t. She was programmed to obey. Her tight ass would stretch around him as he **** his way inside, inch by inch, until his hips were pressed flush against her soft cheeks. The heat, the grip, the way her asshole would clench around his cock, it would feel fucking incredible.

He would start fucking her roughly right away. Hard, deep thrusts that made her whole body jolt forward. Her massive breasts would bounce and slap against the bed with every slam of his hips. The sound of skin slapping skin would fill the room, wet, obscene, loud. Each thrust would bury his cock balls-deep in her ass, his balls smacking against her pussy lips.