Seamus put a condom on, and put the head of his cock against that little dilated orifice, and then, holding her hips tightly, pushed forward.
Asuka hissed again, and said, “Oh!” Then her rectal muscle suddenly gave way and let him in. “Oh.” She breathed slowly, getting used to this intrusion, while Seamus trembled, holding himself just inside her, her muscle just admitting him. At last she said, “Aaah. Yes. But slowly. Please, sensei.”
Seamus smacked her with his right hand, so she could feel she was still being disciplined, and pushed further forward. He took her slowly, feeling that virgin muscle clasp him tight, letting her pause and get used to him each time he made progress. He’d wait until she was again breathing normally before he’d move to take more.
At last they closed with each other, until he was fully in her, belly pressed to her buttocks, cock fully lodged inside her. They stayed together, perfectly still, for a long time.
Eventually it was Asuka who moved, just a very little, and he held himself still while she began to fuck him, in millimeters, then centimeters, always slowly. At last he couldn’t stop himself and moved forward into her as she pressed back at him. She exhaled savagely in response and they fucked hard and fast, forgetting about care or pain.
Seamus could feel his orgasm building until, as orgasms will, it suddenly became urgent. He stopped still, and Asuka swore at him. But in a few seconds he had himself under enough control so he could move again without instantly coming, so long as he moved slowly. That turned out to be good, from Asuka’s point of view.
She began making little noises as he took her, squeaks and little gibbers that he knew as her pre-orgasm cries, her head shaking. So he continued, just a little faster, but pressing as deep into her as he could go, and tightening his grip on her hips so that, he hoped, it hurt her. just enough.
Her little sounds rose in pitch and stopped being little, and Asuka came, wailing and loud. Seamus thought he should really try for more, for her, but he had his own urgencies and his own orgasm was just seconds after hers. Time passed, or stopped, he wasn’t sure which.
When they were more or less conscious and able to speak again he smacked her again, on her right hip, and said, “Good Asuka. Asuka is a good girl, my good girl.” She made a happy sound, though at any other time she’d have laughed at him for saying something like that. They rocked together, vastly pleased with each other, until he started to soften inside her and he had to withdraw, holding the ring of the condom so it didn’t slip off inside her.