"Wow, that's a lot!"
"Holy crap, that's way too much!"
The two of them expressed their reactions as they stared at the massive pool of semen.
Miki clapped her small hands, while Matsuri pulled off her now-soiled knee socks.
After the climax, as my mind gradually cooled down, a growing sense of dread began to creep in.
"Hey, what are we supposed to do with this? It's all dirty now."
Matsuri held up her knee socks, now sticky with semen and pre-cum.
Here it comes, I thought. Matsuri's mockery time. Her half-smirk was like a bad omen.
"You made me spill so much... Did it feel that good to be stepped on?"
Matsuri stared intently at my still-twitching, filthy cock.
She seemed absolutely delighted that she'd made me orgasm with her foot. As if she'd won a mental battle too.
As I slumped in a state of utter dejection, Miki brought over some tissues and began wiping my stomach.
"Seriously, that's a huge mess. You must have held it in for ages."
Miki chuckled and gently patted my head.
She's so kind, despite everything. An angel. A bitch, but an angel.
"Heh heh heh, aren't you embarrassed? Getting wiped down like that?"
"It's okay, Matsuri-chan. Your big brother doesn't mind a little embarrassment."
"Huh? What's that? Gross!"
She's saying all sorts of things about me.
It would be fine if it was just Miki, but Matsuri's presence ruins any chance of feeling sorry for myself.
But why? Why am I being humiliated like this? It's so unfair.
I need to get rid of this stupid little sister... no, maybe I should just teach her a lesson.
Wait, come to think of it, what was I saying earlier? I feel like I was about to say something...
I mentally retraced our conversation so far. As my brain regained its composure, it immediately came back to me.
"Ah, right! It's different, Miki-chan! Matsuri forced me to masturbate!"
I said it. Finally.
Now I'll knock Matsuri, who's been getting so full of herself, all the way down to rock bottom.
As expected, Miki flinched at my shout.
"What... what do you mean by that?"
"I mean, she told me to order her to masturbate..."
"Wait, wait, wait!" Matsuri blurted out, panicking and cutting me off.
But that only piqued Miki's curiosity even more.
"Matsuri-chan, what's going on?"
"Huh? Oh, no, it's nothing..."
"Nothing?"
Miki leaned in menacingly, her gaze intense.
Scary. I don't know why, but this is scary.
Realizing she couldn't brush it off, Matsuri stammered out an explanation.
"N-no, it's just... Miki said it herself, right? That if you order him around, he'll do anything. I just wondered if that was true..."
"I know I said that, but to make her start masturbating right away..."
"U-um, well, she just... she really annoyed me! But still, isn't that pretty normal?"
It's definitely not normal... and she's already left marks on my hands and legs.
Miki's the type to say something like, "Oh, every brother-sister pair does hand jobs," so making her masturbate shouldn't be a big deal, right?
But if this ends with a simple, "Yeah, you're right," I'll never get out of this mess.
"Matsuri-chan, how could you...? Why would you do something like that? I can't believe it!"
Contrary to my expectations, Miki raised her voice in genuine condemnation, her expression intense.
I wondered what had gotten into her, but from a typical perspective, I suppose it's understandable. A younger sister forcing her brother to masturbate... that's pretty disgusting.
"To do something so fun behind my back!"
Wait, is that what you're upset about?!
Miki gritted her teeth, looking frustrated.
"Ugh, you just did whatever you wanted... Now, Matsuri-chan, it's time for your punishment."
"Huh? Punishment... Eek?!"
Suddenly, Miki lunged at Matsuri.
Then, she shoved Matsuri down onto the bed, collapsing on top of her.
"Hey! M-Miki...!"
"This~ is your punishment~!"
"Huh? Wait, you're tickling me! Eek, eek, ha ha!"
"Matsuri-chan, it's the tickle torture~!"
Just as Matsuri thought she'd been pinned down, Miki started tickling her vigorously.
The two of them flailed their arms, grabbing and swatting at each other, giggling and squealing.
Though both were half-joking, there was an undercurrent of eroticism in the air.
"Kyahaha! Stop tickling me, Miki~! Stop, stop, stop!"
As Matsuri wriggled and kicked her legs, her skirt hiked up, revealing white panties at the root of her leg where her knee sock had slipped down.
Just as I expected. This is exactly what I was hoping for. If I'm lucky, I might even get a glimpse of Miki's underwear.
Just as I was about to shift my position,
"Hey, big brother, give us a hand."
"Huh?"
"Come on, hold Matsuri down from behind."
"R-right."
When Miki gives an order, my body moves automatically. My slave mentality is embarrassingly obvious.
Still half-naked, I crawled behind Matsuri and touched her shoulder.
"Hey! Stop it, you pervert! Don't touch me!"
That's when she said it.
But Miki raised her chin and ordered, "It's fine. Do it."
So I boldly grabbed Matsuri's arm and pinned her in a full nelson.
Her upper arm was soft and plump. When was the last time I touched my younger sister's body like this?
Matsuri squirmed and struggled, clearly averse to being touched, but Miki's relentless assault quickly overwhelmed her.
As Miki lunged at her from above, Matsuri's arms flailed futilely, leaving her completely exposed as Miki tickled her underarm directly.
"Come on, squirm, squirm, squirm~!"
"I can't, I can't! Ah, ah-ha! Ah-ha-ha! N-no, stop!"
Matsuri protested, her face flushed crimson, her skirt, shirt, stomach, and armpits all bared. The soft texture and scent of her skin against my body. Miki's hands moved with what felt like deliberate lewdness. All these factors combined, and before I knew it, my penis was standing erect again.
"Kyahaha! No, ah, ah-ha-ha! I can't, I can't! Give, give!"
And that erection rubbed against Matsuri's back as she desperately writhed.
This was an unexpected bonus. Matsuri, completely oblivious to the fact that her shirt was being stained by my penis, just gasped for breath.
As if exacting revenge for what just happened, I began grinding my penis against her back. This is what they call a "backstroke."
"Hey, still tickling you~"
"Kyahaha... Ah, wait, my bra...!"
Suddenly, Matsuri's voice took on a panicked tone.
Judging by how she was constantly adjusting her chest area, the intense tickling must have caused her bra to slip upward.
But Miki paid no heed to Matsuri's discomfort, her tickling growing increasingly relentless.
Her hand, which had been focused on her side, gradually crept upward, passing her armpit and...
"Ngh..."
Matsuri's body jerked involuntarily, and a breath escaped her lips, noticeably different from her previous giggles.
When I looked down, I saw that Miki's hand had reached Matsuri's chest, gently stroking the area.
Matsuri's face flushed with alarm as she protested, "W-wait, wh-what are you touching...?"
"Hmm? What's wrong?"
"You've been hitting it this whole time... Ah!"
"Of course I am! I'm tickling you, silly."
"N-no, I'm not... Ah!"
Matsuri's body jerked again.
"Hmm? What's wrong? Here?"
"Ngh... Miki, you brat! Stop it! Let go!"
Matsuri's resistance grew increasingly fierce.
With her limbs flailing wildly, it was starting to get painful.
Noticing this, Miki finally withdrew her hands.
"Hmm, I never knew Matsuri-chan was such a pervert."
"W-what...?"
"You ordered your brother to jerk off, didn't you? Ugh, you're so naughty!"
Matsuri fell silent, speechless. It was true; it was undeniably perverted.
To be honest, I sometimes wonder if that day was just a dream or something.
If I have to offer one defense, it's that, at the root of it all, Miki was the cause.
If that hadn't happened last week, Matsuri would never have become interested in her brother's penis in the first place.
"What should I do...? Should I tell everyone?"
"N-no! What are you saying?! And why am I even in this mess...? It was Miki who said it anyway—she said we should try giving each other orders or something!"
"She never said 'make her masturbate'! I never thought you'd actually do something like that. Though it's a pleasantly surprising miscalculation..."
Matsuri, easily talked into submission, falls silent.
Miki reached out again, stimulating Matsuri's chest through her clothes.
"T-That's it!"
"What? I'm just tickling you... Hey, wait a minute. Could it be that Matsuri-chan is actually getting aroused by this?"
"N-no way! I'm just ticklish, that's all!"
Matsuri protested stubbornly, but her reaction to the touch was clearly different from before.
Since our bodies were pressed tightly together, I could feel the difference distinctly.
"U-um, enough already! How long are you going to keep this up?!"
"How long? Hmm, I think I might have wronged my brother a little too, so probably until you're satisfied."
Right. I'm the one who's really getting the short end of the stick here.
Miki-chan lightly snapped at me, stepped on me, and then switched positions to step on me again. This kind of thing shouldn't even be happening in the first place.
When Matsuri heard this, she turned to glare at me.
"...Hey, isn't that enough?"
"N-no, it's not. This is still too..."
"Huh? What nonsense! What do you mean... Eep!"
Matsuri's sharp voice suddenly cracked.
Miki's hand began to stroke her chest as if to say, That attitude won't cut it.
"Now, what will you do, big brother? This is still far too lenient to forgive."
"Y-yeah, you're right..."
I agreed without thinking. She was right; compared to what I'd endured, this was still too mild.
But what am I supposed to do? What exactly should I do?
The more I do, the more I realize I'm afraid of the inevitable counterattack. Miki seems completely determined, though...
As my hesitation grew, Matsuri started threatening me.
"Seriously, what's with that dawdling? And this 'until I'm satisfied' thing? I don't like how it's entirely up to you."
There it is. As expected, she's starting to snap back.
So basically, she wants me to give her some clear criteria, right?
Personally, I'd like to keep pressing my penis against her back a little longer.
Besides, watching the two of them tussle is pretty erotic, so I'd like to watch a bit longer.
And I don't like how Matsuri isn't being honest about not feeling anything.
Taking all that into account, I reached a conclusion.
"U-um, well... if you can hold out for another ten minutes, I'll pretend none of this ever happened."
I threw out the suggestion casually, but honestly, I wasn't sure if ten minutes was long or short.
Matsuri seemed to ponder it for a moment before bluntly declaring, "Long. Five minutes."
But that meant I could still continue for five minutes.
When I glanced at Miki, she gave me a big, blinking smile.
Apparently, that meant "OK."
"O-okay, then five minutes."
"And everything we've done so far counts for nothing," Matsuri emphasized with a stern look.
Behind her, I didn't miss Miki's sly, triumphant grin.