Yumi was looking back at Seiji with a strange tenderness.
"Are you hungry already?" she murmured, not taking her eyes off Seiji. "My cutie is hungry."
She lifted her shirt, revealing her pretty, lactating breast, and the baby lazily latched on to it. The sound of the baby's gentle sucking reached Seiji's ears.
At first, his brain screamed for escape.
It was all good and fine for Yumi to play a zen mother, but Seiji never signed up to watch her baby emanating the rhythmic suck-suck-suck sounds around the room.
But his feet didn't move. Seiji felt a peculiar warmth spread through his body. Yumi's breast was full and round, with a subtle sheen to the skin. As the baby nursed, her nipple stretched, with the darker areola visible against the pink of the surrounding skin.
Seiji felt a surge of arousal, despite himself. He was going to look away, but it was too late. Yumi nodded to him.
"Don't be shy, Seiji," she said calmly, her voice a low purr. "You can look all you want. I'm your sister, after all."
Her free hand drifted idly over her hip bone, tracing the curve just visible above her leggings.
The baby stopped sucking, and Yumi sighed. "Such a lazy baby. I still have a lot." She looked around. "Seiji, hand me the breast pump."
Seiji nodded, trying to play it cool, even though he wasn't. When he brought her the pump, Yumi's shirt was still open, her breasts right in front of him, the nipple bright red and swollen from the feeding.
"I don't want to wake her," Yumi said. "Can you attach this thing for me?"
Seiji followed her directions, his fingers brushing against Yumi's skin as he worked. He was no longer disgusted. Touching his sister's body felt fantastic.
As Seiji attached the pump, Yumi leaned back against the pillows. Seiji couldn't help but watch closely the way her breasts rose and fell with each breath, as if speaking to him.
"As you pump, can you massage my breasts, Seiji?" Yumi asked. "It really helps with the milk production, and I'm too tired to do it myself."
Seiji's eyes snapped to Yumi's face. "Okay, sis," he muttered.
He started to massage Yumi's breasts, and a jolt of electricity run through his hands when she let out a soft moan. Yumi's eyes flickered closed.
"Ah, that feels good," she whispered. "You're doing it really well, Seiji."
Seiji's face burned with embarrassment, but he continued to massage her breasts, his fingers moving in slow, gentle strokes. He never thought Yumi's breasts were so nice to touch.
When Yumi turned slightly, her arm brushed against Seiji's crotch.
"Seiji, you're hard," she uttered. "Is that because you like touching my breasts?"
Seiji paused, realizing she understood everything that was going through his head. "S-sis, I-."
"Yes? What do you think about your sister's tits?" she asked, her voice a mix of tease and something else.
"They're... They're amazing," Seiji managed to choke out.
Yumi smiled. "Thanks. It's nothing to be embarrassed about, Seiji, if it turns you on. Men love touching breasts. That's normal."
She gazed at him, her eyes darkening. "Just like women love touching hard cocks."
Seiji's couldn't believe what he was hearing. He paused, astonished. "Really?"
Yumi nodded. "Of course. And I think you already know it, don't you?"
Seiji's heart raced as he felt Yumi's hand reach out and wrap around his erection.
"Ah, Seiji, you're so hard," she whispered with fascination, her fingers moving in slow, gentle strokes. "A cock like this is impossible not to like." He instinctively squeezed her breasts harder, and Yumi moaned again. "Oh yeah, that's good, Seiji, just like that."
Her fingers continued to stroke him, her touch growing firmer. His sister, the girl he'd grown up with, clearly knew how to jerk off a cock.
She watched him squirm. "Are you really enjoying it?" she asked, breathing heavier.
"Yeah," Seiji groaned, his legs trembling. "Y-you're good at this, sis."
He didn't lie. Her long fingers felt great wrapped around his cock.
She smiled. "Am I?" she whispered. "How good? Do you want to cum, Seiji?"
"I want to…" He caught himself.
Yumi's eyes grew darker. "Say it, brother."
"Yes," Seiji repeated, bolder this time. "I want to cum, Yumi"
She leaned closer, pulling his cock to freedom and continuing to work his shaft. "Then cum, Seiji," she whispered, her voice husky. "Let go. I want to see you cum."
Seiji's tried to resist Yumi's touch, but he couldn't. The sensation alone was too much to bear. But when you added the way she gazed into his eyes, the heat practically oozing, he definitely couldn't last long. He had to cum.
With a loud groan, Seiji started shooting his sticky cum onto Yumi's leggings. After the first splat, another two big ones followed, all of them white and hot. Yumi kept smiling as she continued to stroke him, milking him for every last drop.
"Wow, that's a lot of cum, Seiji," she murmured. "I'm impressed. Did you build it up for a while?"
Seiji only shook his head, trying to catch his breath, while Yumi gazed at the stains on her leggings, her fingers twirling strands of Seiji's cum. "I'd better wash this," she said, matter-of-factly.