They'd been researching Norwegian Ridgewickles for eighteen months when he asked. The ridgewickles (scaly little symbiotes that live on Norwegian Ridgebacks, feeding on the vegetation caught between their scales), made a fascinating study, seeing as they were only visible when they were warmed by the dragon's skin. Together, Luna and Rolf had developed a viewing table, made of ridgehide and warmed from underneath by temperature-controlled flames. It was a wonderful innovation and allowed them, if they were careful, to transfer the beetle-like creatures for study.
Indeed, the research would be groundbreaking, but it was almost over. "Luna?" Rolf asked as they were tabulating the last of the results. "The study's coming to an end now, but I can't imagine my life without you. Would you consider getting married?"
"Oh, certainly," Luna replied - and considered it as her quill scratched loopy pink numbers over the parchment. At length she decided, "That seems like a nice idea; but I can't imagine we'll have sex."
"Oh no," Rolf agreed, and the comfortable silence resumed for a time. His mind, scattered but brilliant, soon twitched in another direction. "So, where do you think we should publish?"