Morning, Shelly's room. Its occupant was asleep on her bed, laid on her belly and with her limbs all over the mattress. Her blanket was only covering her back. She apparently had gone to sleep late, hence the disarray.
Someone knocked at the door. She didn't reply.
"Shelly? Get up! You'll be late for school." It was Stan. After ten seconds or so, there was still no answer. "Alright, I'm coming in." He declared, then entered.
Inside, he was momentarily taken aback by the state his sister had put herself into. She usually slept more comfortably.
"What the hell…" Stan muttered, then resumed his task of waking Shelly up. "Shelly, come on! Mom's calling!"
He was performing slight pushes on her back, but they had no effect. She remained asleep. Determined and annoyed, Stan decided to go further. He moved closer to her feet and held both his hands in the air, like if he was going to grab something.
He then placed his hand on her buttocks, and started pushing again.
"Shelly! Come on! Wake up!" He exclaimed, almost through gritted teeth.
This time, Shelly responded. She moaned and shook her head, slowly regaining her consciousness. Then she saw what Stan was doing, and her shock fully awakened her. She instinctively reacted by kicking Stan's abdomen, thrusting him away from her and causing him great pain in the process.
"Ouch!" Stan stumbled.
Shelly then furiously raised from her bed and held Stan by his jacket. A few veins could be seen bulging in her forehead.
"What the fuck do you think you're doing grabbing my ass, you little pervert?!" She growled, gradually raising her voice.
"I was trying to wake you up!" Stan answered, sweating profusely.
"By grabbing my ass?!"
"Hey, you hammered my ass yesterday, remember? You're in no position to complain!"
Shelly tossed Stan off her grip. "I apologized already!" She put her hand on her face and started pacing around her room. "Seriously, Stan, I expected you to be better than those perverts at your school!"
The tone of disappointment in her voice was palpable. She thought Stan was now on the same level as the Eighth Graders, whose depraved antics really irritated her.
"Oh, come on, just because I touched you somewhere you don't like?" Stan protested. "What if I kissed you to wake you up? Would you think of me as a pervert too?"
"No, I would think of you as a weirdo." She leaned toward Stan, confronting him. "So you wanna kiss your own sister, huh?"
He scoffed. "See, you always think the worst of me, even when I try to be nice to you. You wouldn't know fraternal love if it hit you on the face!"
"Fraternal love, my ass!"
"Fraternal love, your ass, indeed." He spoke under his breath.
"What was that?"
"Nothing!"
Shelly was now fed up with all the squabble. As if she wasn't irritated enough with Stan's method of awakening her.
"Look, enough of this! You came here to wake me up? Mission accomplished. Now fuck off, I gotta get ready."
Equally annoyed, Stan left the room without saying another word. Shelly was now by herself, waiting for the heat of the discussion to go away before doing something about her appearance.
"Pfft. Fraternal love…"
Bathroom, fifteen minutes later. Shelly was taking a shower. Suddenly the door open and she peeked through the box to check who had entered. It was Stan, with only a towel around his waist. She opened the box door and exposed her still wet head through it to face him.
"Hey! What the hell are you doing here?" She questioned.
"What? I'm gonna take a bath too." He answered.
"Well, go wait outside!'
He held a toothbrush and a toothpaste on each hand. "I'm gonna brush my teeth first, may I?!"
She relented, not wanting another discussion. "Fine, just don't come here." And went back to her shower.
Stan shrugged it off and applied the toothpaste on his brush. He put it into his mouth and make vigorous movements with it for around a minute. When he finished, he spat all the foam that had formed and washed the inner of his mouth with water.
Suddenly, he heard Shelly shriek, and then a thud.
"Shelly!"
Alarmed, Stan rushed to the box, ignoring her warning from earlier. He opened the door and spotted his sister, naked, wet and fallen on the floor. She was disoriented and grunting. Stan knelt before her.
"Shelly, you okay? What happened?"
She rubbed her hand on the left side of her head. "Ugh… I dropped the soap, and slipped on it… I think I hit my head."
"Come on, I'll help you." Stan lifted Shelly off the floor and carried her to the toilet, which was with the lid down, where she took a seat to rest. He comforted her.
"You okay?" He asked again.
"I'm fine. Just give me a minute." Five seconds had passed before Shelly realized something. "Stan?"
"What?"
"We're both naked here in the bathroom, aren't we?"
"Huh?"
Then Stan realized it too. In his panic to aid Shelly, he had dropped the towel that was covering his genitalia. He was now completely exposed in front of her.
"Oh, shit!" He yelped. "Sorry, I didn't notice! I heard you falling, and then I didn't think-"
"Okay, okay, I get it." She interrupted. "It's my fault anyway. I can deal with this."
Maybe it was her dizziness, but Shelly wasn't in the mood to get angry at Stan for seeing her naked for the third time. Or maybe it wasn't. She secretly appreciated when Stan worried about her, enough to put petty matters about their mutual nudity aside.
But then, Shelly spotted something and facepalmed. "Ugh. Stan…" She sounded exasperated.
"What?!"
"What's that down there?"
She asked that while pointing between Stan's legs. More precisely, his penis. To his utter surprise, it was erect. He blushed until he was red as a pepper, and then he placed both his hands over it, visibly embarrassed.
"Th-this was involuntary! Ph-physiological!" He gagged. "Y-you know, you're here naked and… e-even with you being my sister, you look pretty… y-you know…"
"Yeah, I know." She resigned. "Look, because you went through the trouble to help me, I'll let this slide. Now please, get your towel and wait outside."
"S-sure."
Stan hurriedly picked the towel from the floor and exited the bathroom. Shelly was alone again. But this time, she didn't want to think about anything that happened. Or anything at all. Her head still hurt.