Sakura, it was Sakura. There was no mistaking that plum-colored hair, nor the ribbon that fastened it to the side.
It was her sister.
Why was Sakura here?!
She would never do this?!
A more cynical side of her mind then replied.
'Are you sure about that? You never knew her. Maybe she's like you, a pervert. One that gets off on being used.'
Rin shook those thoughts away and tried to make sense of this as quickly as possible. So she defaulted to her magus mindset as her rational side and horny side were of no use at the moment.
If Sakura as a person wouldn't do this, then Sakura the Magus might. It was likely a similar situation to her own. Gathering a stockpile of magical energy for the coming Holy Grail War. Rather than optimizing her own production and quality as Rin did, Sakura took to sheer quantity by gathering it from the masses.
It seemed the two of them were more alike than she thought. Giving up their pride and dignity to get ahead in their craft.
Her lustful side then chimed in.
'Or maybe the two of you are simply perverts.'
She… did not dismiss that thought as a possibility. In the past two weeks, Rin had discovered quite a bit about herself. Such as how far she was willing to go to satisfy her libido.
But at the end of it, her sister was in a toilet and had been having sex with who knows how many men.
Rin's eyes darted around taking in her sister's bound form. The sight was unreasonably arousing. With her big soft breasts, each capped with a pale pink nipple that was unbelievably erect. A primal feeling welled up at the sight of them, she just wanted to pinch and bite them to make her squeal.
Then her eyes went lower to Sakura's gushing hairy hole. It was so inviting as the swollen lips pulsed with need and leaked copious viscous juices.
Her bound limbs only added to Rin's lust. It was as if Sakura was no longer a woman or even a living being… but a toilet. A receptacle for piss and cum. A place to needlessly dump filth.
Rin's penis had never been so hard. Her stud glowed as if in response to her desires. Blood vessels then bulged as blood rushed powerfully into her penis giving the organ an almost inhuman texture with the myriad crisscrossing veins.
Rin's breathing grew heavy as her mind was clouded with desire. She was about to lose her virginity and to her sister at that! That thought only made her more aroused.
Rin felt another part of her break once again.
Rin felt her mouth make a hungry lewd grin underneath her mask. One that she would have never made before, but now felt… natural.
She gripped her diamond-hard penis at the base and beads of precum streamed down from her pisshole.
She liked how that sounded. It was so vulgar.
She already discarded her pride as a magus so what was using crass and vulgar words to her now? Nothing that's what.
She laughed as she thought of her father rolling in his grave about his heir degenerating into a crass lecherous brute.
Rin then took a step and slapped the pink crown of her cock against her sister's sopping-wet hole. She then teased the entrance by smearing her copious precum against the entrance, as if marking her territory.
Sakura squirmed from her light teasing. She looked up at her with a needy face, "Please mess me up already!"
If only Sakura knew she was saying that to her sister.
Rin lined up her cock and leaned in, "Sure thing, Sakura."
Before her Sakura could react, Rin slammed herself into her sister and soon found herself in heaven. It was so delightfully hot and wet. Her sister's folds clung so pleasantly to her shaft and the way the undulated felt so absolutely wonderful.
Sakura's shout of surprise quickly turned into one of pleasure, "Ahn~!"
Rin then felt every once of control leave her. She powerfully, yet unskillfully pistoned her hips as she sawed in and out of Sakura's velvety folds with the power granted from years of martial arts training.
With every thrust, the crown of her dick dug just a little deeper into her sister's pussy.
Rin was momentarily distracted from her thrusting by her sister's bouncing and jiggling tits. With every thrust, they bounced and rippled. She then roughly grabbed them and groped them with jealousy. Why were they so damn big!
She pulled and pinched Sakura's nipples and had to bite her lip as her sister's cunt contracted wonderfully tight.
Her mouth moved out of her control, "Who knew that such a demure girl like you was such a slut!"
Sakura wiggled her hips and the walls of her cunt undulated in a most pleasing way as they tried to milk her.
Sakura looked pleadingly at her, "P-please don't, Ahn~, tell anyone at school!!"
Even in her most lustful moments, she wouldn't betray her sister like that. But even then Rin felt her mind focus on only one thing, her pleasure.
Rin roughly tugged on Sakura's nipples and her sister's pussy grew tighter still.
Rin then grunted as she felt a torrent of cum just waiting to be released, "Just milk this load out of my dick you whore!"
Rin sped up her thrusting and soon enough she felt her testicles clench as her thick semen rose up.
Rin then twisted her sister's nipples as hard as she can while she yelled, "Cumming!!"
She then felt her sister's cunt squeeze her like a vice and she let out a pleased moan as she released her steaming hot semen.
She watched as her sister's stomach bloated just a bit from how much semen she pumped into her and after about a minute she finished. Her softening dick slid out of Sakura's pussy and thick pearly white seed poured out of her.
Rin huffed as clarity returned to her but before she had a moment to think she was pulled out of the toilet as a fat man took her place. She caught sight of the man's penis and it was massive. A moment later she heard Sakura's cries of pleasure… that sounded much louder than what she made with her.
Rin then felt a bit self-conscious.
One of the old men that brought her here patted her on the shoulder, "Don't worry about not stacking up to the rest of us kid. You got a pretty decent tool yourself and you're young anyway so it will get bigger in time. You cum like a racehorse though so you got a bright future."
Rin then looked to the line and saw many of the men rubbing their massive bulges to the sounds of Sakura's moaning.
She knew what she had to do but in the meantime, she had to go home, "Thanks. I guess. I'm going to head on home for the night."
The man then slipped her a card, "If you are still feeling a bit down about your size the best you can do now is get better at using what you got. So if you want to learn a thing or two head here and tell them Kubo sent ya. They will hook you up with some primo 'training' videos."
She took the card slowly, "Sure," she looked at the card and it was to a normal video store oddly enough, "Thanks."
The man patted her on the back, "No problem kid. It's always fun to introduce more people to the pleasures of fucking bitches right! There will always be frustrated women that need some proper loving and we are willing to give it!"
"I… see."
In her post-ejaculation clarity, she found the conversation absolutely strange… but her lustful side roused briefly at the prospect of having more better sex. So she pocketed the card and left the clearing that still echoed with Sakura's moans. She licked her lips at the delightful sound and as much as it irked her to hear it was the product of other men. She still wanted to hear more of it.
"How often does she do this?" She asked.
The man gave her a lecherous grin, "About every weekend. She's usually set up about sundown."
Rin nodded and filed that away for later use.
Rin then retrieved her things and went home determined.
She was going to put in a second jewel.
She wasn't about to have some strangers pleasure her sister more than she could!
She might also make a run to the video store to pick up a 'training' video. If her technique was lacking then all the size in the world wouldn't matter.
There was no way she would half-ass something like this! Her pride as a Tohsaka demanded it!