Why Did the Holy Knight Get Cursed with XX?

Loarna and Celesto were friends. At least until five years ago. Driven apart by certain circumstances, the two reunite when Celesto is unexpectedly struck by a curse. "A curse of lust? Where? When? Do you know who cast it? A person? Or a demon?" "...Are you more curious about this curse than I am?" A curse where sexual urges cannot be relieved unless pleasure is shared with another. For a handsome man from a prestigious family, it might be a curse he could live with without even needing to break it, but... "...But you're a holy knight." The problem is that Celesto is a holy knight. Specifically, a holy knight of the Temple Order, who faces immediate dismissal upon losing his purity....