Kaiba-san's got big ropes tying his ankles. He's got big ropes tying his wrists as well. And there's tape on his mouth, but Yami no Yuugi says that part's his fault, because he wouldn't be quiet.
Kaiba-san's naked, too. Well, they're all naked. She's naked, and Yami no Yuugi's naked. Right now, he's got his naked parts pressed right up against hers, and it feels sort of good. She could really get to like this.
"Open your legs," he tells her, and, like a good girl, she obeys. "Wider," then he kisses her, hard, while she tries to decide if the other thing he's doing hurts, or if it feels really really good.
"Ooh, Yami no Yuugi-san..."
"Be quiet," he says.
"Don't you want me to tell you if it feels good?"
he holds still for a minute, just long enough to answer her question. "Tell me afterward," he says. Then he's moving again, and the bed starts bouncing underneath them. And she kisses him just as hard as she can, but mostly so she can stop herself from squealing.
And poor Kaiba-san's still tied up by the side of the bed, but to tell you the truth, Shizuka doesn't even think about him, not for a long long time, not until Yami no Yuugi's done, and he says she's allowed to talk again.
"Can we untie him now," she says.
"Tell me how good it was first."
"I... um..." She can feel herself turning pink.
"That's all right," Yami no Yuugi tells her kindly, "I know it was good."
"Is... is Kaiba-san going to get a turn?"
Yami no Yuugi's started untying him now. He shakes his head. "Of course not, I won."
She watches as the ropes come off. "Maybe if he duels you again and you lose?"
"I won't." He pulls the tape off. "Not against him," and that's when Shizuka realizes why Kaiba-san had to be tied up. And why he had to have his mouth taped shut. Because once he's free, and he and Yami no Yuugi face off against each other, no one even remembers her any more, and she has to find her own way home.