Prompt: Oxford Teslen AU, Nikola accidentally compromises Helen's reputation and they have to get engaged to save it
Of all the things Helen had ever expected to see, Nikola Tesla down on one knee, looking up at her with mingled affection and sadness and hope in his soft blue eyes was not one of them, but there he was, her hand clasped loosely in his as he waited for her answer.
"Nikola, you know how little I care for such things; I would not chain you to me for eternity simply for society's sake," she said gently, expecting her refusal to lighten his spirits, but to her surprise the sadness in his eyes only grew, and he said, his voice very quiet, "But it would make your work at the Sanctuary much easier, my dear, and it would not be a burden at all: at least, not to me, though of course if you feel otherwise – "
He stopped, because she was giving him the smile that only Nikola could inspire, her answer written plainly on her face; Nikola lit up with a brilliant smile of his own, and when Helen drew him to his feet, he melted into her arms.