As much as it was killing him, the Doctor kept quiet as he was led through the castle to Rose. He couldn't risk insulting them again. Finally he was pushed through one last doorway into a bedroom, the door snapping shut behind him.
"Rose!" he said, worries that he had refused to acknowledge put to ease as he caught sight of her, "I-" but then he noticed what she was wearing.
The dress was made of a velvety red material. It was strapless, and very tight, flowing elegantly down to her ankles. Truthfully the only parts of it that clearly registered to the Doctor were the slit that rose from the hem, nearly to her hip, and the ridiculously low neckline.
"Wow," he managed after blinking very hard a few times, "That's very, uh, I mean…just, wow." He swallowed, and found it much easier to talk when he wasn't looking at her, so he stared at the ceiling and continued.
"But it's not very practical. I mean, we do have to escape, you know," he said, pretending to be very interested in the room's architecture. He jumped slightly at her touch, and looked down to see her standing very close now, and toying with the buttons of his jacket.
"We'll escape later, yeah? Let's have some fun," she said seductively, closing the gap between them with another step forward.
"Actually Ja-" he began, but was cut off when Rose pressed her lips to his and forced her tongue into his mouth. Under any other circumstances he would have been delighted, but right now something felt very wrong.
"Mmpf!" he protested, trying unsuccessfully to pull away from her. Soon she had pulled his jacket off of him, and breaking off the kiss for a moment, she grabbed his shirt and pulled it over his head, throwing it aside.
"Don't you think we should-" he tried again, but she went back at him with renewed vigor. Her lips now glued to his and her hands on his shoulders, she swung him around, and moved forward, forcing him back until his calves were pressed against the bed. In one swift move she grabbed his hands, which were trying to push her away, and placed them on her hips. Then one hand wandered his across his bare back, and the other rubbed small circles at the base of his neck.
Finally she had to come up for air, and taking advantage of this, the Doctor tried to protest again.
"Rose, I-oof!" She had pushed him down hard on the bed, so that he was now lying on his back, while she hovered over him. She used one hand to support his head so that she could continue kissing him while the other had wandered determinedly towards his waistband. It took him a moment to realize that she was attempting to undo his belt, but when he did, he grabbed her wrist and used his other hand to push her off of him.
"Rose," he said, with great concern, "Why are you acting like this? What'd they do to you?" He looked into her eyes, and noticed for the first time since he'd entered the room, that they were a pale, empty gray. He pushed her away.
"You're not Rose," he said softly, horror in his voice, "You're not Rose!" he was yelling now, "I don't know who you are, I don't know what you've done to her, but you are not Rose!"
He jumped off the bed, not taking his eyes off of the Not-Rose. He backed away from her, stopping to grab his jacket and shirt. Once he had them, he turned and ran, as fast as he could, away from the thing, that was very much not his Rose.