Not really

“I recognize you as my lord and master, a member of Alpha 7 who has triggered me. How may I be of service master,” she said as she bowed her head again, her long wet black hair falling forward over her massive breasts.

Mason was insanely turned on by how submissive his sister was being. The way she stood there completely naked, water dripping from her stiff nipples, head bowed, waiting for his command, it made his cock throb hard inside his wet jeans. He had always had a crush on her, but seeing her like this, so obedient and ready, made that feeling ten times stronger. He hated that his body was reacting this way, but he couldn’t stop the rush of heat.

He had to make things right though. This wasn’t his sister. Not really.

“Wait, you said there’s a phrase to make you come out of trance right? What is it?” Mason asked hopefully.

“I apologize master,” Serena said, still in that calm, emotionless voice. “I am not allowed to have knowledge of my own triggers, in the event that my cover personality becomes aware of it.”

“Cover personality?” Mason asked, frowning.

“My cover as Serena Vale, a university student studying English literature. My masters made a backup of this body’s original personality to ensure people who know this **** don’t become suspicious when I’m not being used.”

Mason felt a pit form in his stomach. A backup. Like she was just software they could switch on and off. His big sister, the one who always called him her favorite person, was being treated like a toy with a spare personality saved somewhere. The thought made him feel sick and angry at the same time.

He looked at her standing there, still completely naked, water slowly drying on her olive skin. Her massive breasts rose and fell with each steady breath. Her light brown eyes stayed fixed on him, patient and empty, waiting for whatever he wanted. No shame. No resistance. Just total obedience.

“So… the real Serena is still in there somewhere?” he asked, trying to keep his voice steady.

“The cover personality is stored safely. It can be restored when the **** is decommissioned or when the masters decide it is time to return to normal life temporarily,” she explained like she was reading from a manual. “Until then, I exist only to serve.”

Mason ran a hand through his own wet hair, trying to think. His jeans were uncomfortable now, his hard cock pressing against the wet fabric. Every time Serena shifted her weight, her heavy tits moved slightly, drawing his eyes no matter how hard he tried to focus on her face.

“And you really don’t remember being my sister? All the stuff we went through growing up? Mom being abusive, you always looking out for me?”

“I have access to the memories of the cover personality when needed to maintain cover,” she said. “But right now I am **** Serena. Those memories are not active unless required for service. How may I serve you, Master?”

The way she said “Master” sent another unwanted jolt through him. Mason felt his face heat up. Part of him wanted to tell her to put some clothes on. Another part, the darker part that had been growing since he first saw her on the floor with the baseball bat, wanted to test how far this obedience went. He pushed that thought down hard.

“This is fucked up,” he muttered, more to himself than to her. “They turned you into this… thing….”

Serena didn’t react to his words. She just stood there, hands at her sides, massive breasts on full display, waiting. A single drop of water ran down the underside of her left breast and dripped off her nipple onto the tile.

Mason swallowed. “If I tell you to do something… you’ll just do it? No matter what?”

“Yes, Master. That is my purpose. I am trained to obey any command from a triggering user. My body belongs to Alpha 7 and whoever uses the correct phrases.”

He thought about the frat house again. Alpha 7 in Washington. How many guys had used her like this already? How many times had she been passed around or commanded to do shit like what he walked in on? The idea made him angry, but it also made his cock twitch again. He hated himself for that reaction.

“What if I tell you to stop being like this? To go back to normal right now?”

“I cannot obey that command, Master. Only the decommissioning phrase or direct orders from the primary masters can restore the cover personality. I do not have access to that information.”

Mason paced a couple of steps in the small bathroom, his wet socks making squelching sounds on the tile. Serena’s eyes followed him calmly. She didn’t cover herself. She didn’t ask why he was still staring at her body. She just waited, obedient and ready.