Her brother

Before she made it out the door, she heard a familiar voice behind her. "Aren't you forgetting something, oneesan?" Her brother said smugly, holding one of the plugs in one hand and something behind his back with the other.

"Geez, couldn't even make it out of the house without you catching me." She giggled and gave her booty a shake at him.

"Hey, wouldn't you rather have me fill you up than some stranger? Now close your eyes." He said. She did, and then began to moan as she felt something huge being pushed into her tight asshole. Her brother smirked as he pushed the huge watermelon all the way into his sister's ass as she moaned. He'd coated it with aphrodisiac liquid, ensuring she'd be an even bigger slut than usual today. He finally worked it all the way in. "Can you guess what it is?" He asked.

"Mmmmmph..." She moaned. "Something big...a jug of milk?"

"Nope!" He said and slapped her ass hard. "Have fun today, oneesan!" He said as she awkwardly made her way out with the gigantic object jammed up her ass, making her squeak and moan with every movement.