Yes, he's too invested now

The man on the call kept going, voice dripping with mockery.

“Bet your little brother has no idea what a dirty fucking slut you really are. Does he? Does he know his precious big sister is currently ruining her cunt with his baseball bat on camera for me?”

Serena whimpered, pushing the bat even deeper. Her toned thighs shook as she fucked herself harder.

“No… he doesn’t know… please more, I want more…”

Mason’s stomach twisted. She was talking about him. While she was doing this.

He couldn’t take it anymore. Whatever this was, it had gone too far. Something was seriously wrong here. Serena wasn’t the type to let some random guy talk to her like that.

Was she being blackmailed, he wondered? The thought hit Mason hard as he stood there frozen at the cracked door, eyes locked on his sister on the floor. Maybe that guy had something on her, some old photos, some video from university, anything that could **** her to do this. Serena had always been careful, but people made mistakes. Or maybe she owed him money. Or maybe it was something worse. His mind raced through every possible explanation while his stomach kept twisting.

He was almost zoning out when he heard the man ask her to stop. To his shock, Serena did so without any resistance. Her hand simply loosened its grip on the baseball bat. The thick wooden handle started sliding out of her pussy with a slow, wet plop, leaving her stretched hole gaping slightly for a second before it started to close. A thick string of her juices connected the bat to her pussy for a moment before it broke and dripped onto the carpet.

The man spoke again, his voice calm and commanding through the laptop speakers.

“Watching you fuck yourself is fun and all but I don’t think a slut with udders like you is even fit to be considered human. You should just act like and believe yourself to be a cow.”

He then clapped his hands twice. The sound was sharp and clear even from the hallway.

Mason watched as the light left his sister’s eyes almost instantly. Her light brown eyes went completely glassy, empty, like someone had flipped a switch inside her head. She dropped the bat which slowly plopped out of her pussy the rest of the way and rolled a few inches across the carpet. Serena turned around without a word and got on all fours. Her massive breasts hung heavily beneath her, swinging like pendulums with the movement. She brought her face down to the carpet and seemed to sniff it, her nose pressing into the fibers for a few seconds. Then she tried to chew on it, her full lips opening and closing around a small bunch of the carpet threads like she was actually trying to eat grass.

She then raised her head, looked straight at the laptop and let out a loud, deep moo.

“Moooooo!”

The man on the video call burst out laughing, loud and genuine.

“Dude you were right she’s totally a cow now. Watch them udders…”

Serena’s heavy tits swayed heavily under her as she shifted her weight on all fours. She mooed again, softer this time and lowered her head once more to sniff at the carpet.

Mason’s jaw was on the floor. What the fuck was happening. Had his sister gone insane? This was beyond kinky. This wasn’t some roleplay that had gotten out of hand. Something was definitely wrong. The way her eyes had gone blank in a single second, the way she obeyed without any hesitation or shame, it didn’t feel like acting. It felt like she had actually become something else at that moment. His straight-laced big sister, the one who used to scold him for leaving dirty socks on the floor, was now naked on all fours mooing at a stranger on a video call while her pussy still glistened from fucking herself with his baseball bat.