Back at home, Leo and Sarah were intensively fighting over the game controller. Sarah's foot was pushing on Leo's face as he struggled to reach his hands towards the controller in Sarah's bosom. Fortunately, both of them were careful about not exerting too much force and avoided breaking the relatively fragile equipment; the sister's soft marshmallows also served as valuable cushions for that purpose.
"It's my turn!"
"Just let me try one more time! Pleaaaase," Sarah begged and Leo yielded to her sparkly puppy eyes.
"Fine."
They were playing Dark Souls IV, a gruesome game that took pride in making its players suffer, and was known for its difficulty combined with the deep lore. It was the nth time that the sister had died in the same spot; Leo anticipated a nth+1 death in the next few minutes.
Sarah knew she was being a little bit unreasonable and thought of an idea to compensate for that. She got close to Leo and sat down on his lap.
"This is so that we can play together… help me get pass this level please~~"
Sarah was wearing pantyhose with a short skirt. Her rear was rubbing against Leo's dormant dragon as she pulled Leo's hand across her waist to the controller under her great bosom.
"What are you doing Sis? This makes it harder to play," Leo tried to ignore the feeling on his crotch and wrist and mildly protested. His face began to flush slightly red.
"Hehe, this is what makes it fun. Mom used to do this when we were younger. Just that now I get to sit on you."
Leo recalled the days when he sat on his mother's lap and had the weight of her massive bounty resting on his head. He used to complain that was the reason he could not get tall.
They tried their best to complete the level and finally beat it by a stroke of luck. amidst their cooperation, Sarah purposely twisted and moved her body to provide enough stimulation for little Leo to wake up.
Sarah's goal is to eventually fully embrace Leo as her partner. She cannot keep their sexual activity during his sleep a secret forever. One way or another, they needed to face each other on open terms. However, she was afraid of one thing after she witnessed the potential of what Leo could do. Leo's stamina and prowess when he is fully serious in heat was something Sarah knew she could not handle. She often dreamed of herself losing all of her personality and becoming a mindless sex slave for her little brother, craving for his monster perpetually. It sounded absurd but that was a half serious reason; simply speaking, she had been fantasizing becoming a devout worshipper of Leo's monumental tower in her wet dreams that she scared herself of it ever becoming real.
Now, with their mother and aunty out of the house, Sarah's plan was to use this opportunity to slowly indoctrinate Leo by taking the lead in their sexual engagements. Teasing him like this was a good start. By the time they beat the level, little Leo had been fully awake; it rose above her buttock and rubbed into her back.
Leo was extremely embarrassed and did not know what he could do to hide his extraordinarily oversized erection. Sarah gently smiled at her little brother's cute embarrassed face.
"uhm Sarah, I don't know what happened, but this thing just keeps getting bigger overtime, but I never seen it get big like this," Leo still thought no one knew of his big secret, while the entire family already had up close and personal, negative distance contact with the great beast. Needless to say, the constant bulge in his pants everyday was impossible to hide.
"It's ok Leo, it looks painful, let your sister have a look. I will help you take good care of it." Her gentle smile slowly turned seductive.
She turned around and kneeled down to face the throbbing tower, removing the stretched cloth covering its mass. Marveling at its usual greatness, she began to stroke it, then looked at Leo with a teasing grin. Leo was still embarrassed and was hesitant to look his sister in the eye.
Sarah could not be helped from holding back her lust and started to service the great mammoth at the tip with her tongue, which quickly turned into taking the tip in the mouth, then eventually deepthroating the monster. She was ferocious like always; Leo could not grasp what he was seeing and remained bewildered.
She took the behemoth deeper and deeper into her throat, until finally, the bulge from her throat extended to her upper chest. His whole rod was inside Sarah, Leo felt inexplicable stimulation along his whole length and a strange sensation began to well within his twin orbs.
"Sarah...! I feel strange, can you slow down?"
She knew Leo was close to climaxing; his twin orbs would always painfully expand in size just before his ejaculation. Sarah then hugged Leo's waist and pushed her face down as heavily as she could into Leo's nether region. Hot viscous ooze began pumping directly into her stomach while she drenched her black pantyhose and sprayed her clear fluids onto the game controller. She finally let go of the girthy rod and kissed the tip again as it departed from her lips.
"Uhm… I am so sorry sis; I think I let out a lot of stuff inside you," Leo's young face flushed red as he was very embarrassed about what happened.
"Don't worry about that, I should thank you for the meal instead. How did that feel, little brother?"
"It felt warm and really strange at the same time. I don't know what to say."
"Hehe," Sarah flicked her finger at the towering rod, "I see you are still in pain let's try again to soften it up. This time let me tell you what to do. Now, stand up."
Sarah could not hold back her urges. Her plan failed before it had even begun as she could not resist the temptation of being thoroughly dominated by her little brother's massive behemoth. The thought of what she was about to do alone brought her to another climax in secret. She kneeled on the ground once again and grabbed Leo's hands to place them on the sides of her head. She pulled down the great towering rod and leveled it with her mouth.
"Now Leo, push and pull my head down on your monster gently when I give you the go. If I make a peace sign like this, it means you should go faster and harder."
"Are you sure this is alright? I think it will hurt you."
"Don't worry, your sis is quite durable."
Sarah stuck out her erotic wet tongue to embrace the massive rod as she gave Leo the signal to go. With just a gentle pull, the girthy glans from Leo stretched his sister's mouth and the tip was already stuck in her throat.
Leo moved at a slow rhythm to not hurt his sister, but Sarah was already too impatient and made the peace sign. He began to thrust her head faster, his girth rod sliding deeper into her throat. Yet, she still held her hand up in the air with a peace sign and Leo obediently followed the order.
Sarah forgot to lower her hand as she was too engrossed in having her mouth and throat used as an onahole. Leo's strong and firm hands seemed to start pushing her head down without mercy, while loud and obscene gulping sounds resonated from Sarah's throat after every thrust. Her eyes had already rolled back but still kept her peace sign high in the air. Leo was not sure what to do and continued to follow the order from the sign. Out of consideration, he lowered the acceleration to slow down the time to reach his full thrust.
Leo's carnal desire had slightly taken over as the sensations stimulating his brain and rod got stronger. He became too excited to pay attention to his sister's broken gesture. Eventually, the thrusting motion reached peak frequency and swelling began to appear from Leo's already massive twin orbs.
He still retained his awareness, he noticed the same swelling and was not going to make the same mistake again. At the moment of climax, he wanted to pull his monster out but Sarah hugged his waist tightly and to keep the monster deep inside her. Another full liter of thick ooze was pumped directly into his sister. After the deed was done, she was finally set free of Leo and his partner in crime.
Sarah's mouth was not able to close and she had to face the ceiling to prevent her hard-earned meal from spilling. Leo got too excited and had a little more blood pumped into little Leo, which expanded his girth by another ring size. She had to pull down and push her chin to adjust the desolated jaw. Luckily, her superman constitution ensured that her head was still in one piece.
"Are you ok Sarah? Maybe we shouldn't be doing this," Leo was still dubious of their actions.
"That was so hot! But it looks like you are still in pain…."
Sarah already had an inflated stomach and her doctor would suggest that she not overdose on her prescribed amount. She was only able to bring Leo to the shower to cool down the erection with cold water while she rubbed the monster between her thighs to get several more loads out into a container. It was very tempting to let the monster slip inside her once again, but then the worst could really happen and she was still sane enough to know she was not ready.
"Leo… I am still your sister and you are my cute little brother. Don't let what happened today stick in your mind but come to ask your sis for help anytime!"
After a short counseling session by Sarah, they went back to play DarkSouls IV as if nothing happened. Though, Sarah was thinking about skipping lunch and dinner to digest and save room for a late-night dinner.