Tristan shut his eyes, his lips pulling into a wider smile even as she leaned forward to kiss him more deeply. He drew in a long breath when she moved onto his lap, and one arm twisted around her waist, his other hand coming to rest on her leg, as though to help keep her up - not that she needed any help, clearly. Her skin felt a little cool in the night air. He liked it.
He kept meaning to suggest that they go inside, to find somewhere more comfortable to sit - but every time he focused enough to form a coherent question, he found another reason not to move quite yet. The feeling of her pressed flush against his chest wasn't something he wanted to disturb; he thought that if he lost that pressure of her thighs against his, he would surely be too cold; when his hand crept up her back and into her hair and he kissed at her throat, moving just seemed absurd.
"Please stay, then," he murmured, when he had a moment. "I don't ... Sending you back to the library would be a little much to take." Too many students prowling about, none of them up to any good. He didn't like the idea at all, all of a sudden.