The Dragon Warlord's Fictitious Wife

Once, a dragon came to my house for help—and got it. The price was simple: one year of a fake marriage, to protect me from the claims of other dragons at the academy, because an orphan with a strong gift might attract many. We signed a marriage contract and went our separate ways, convinced we’d never meet again—but we did meet again at the academy. Now he’s my professor, and also the most attentive observer. I have many secrets, and he wants to uncover each one. How can I keep them—and at the same time protect my own heart from the claims of a pretend husband?