Flower of the Sun by Harvey

Plot: Zigrien, the illegitimate son of a noble family, is forced to become the apprentice of Idris—the ruthless leader of the Knights Templar, who serves directly under the Crown Prince. Tasked with uncovering Idris’s weaknesses, Zigrien hopes to stay unnoticed by the man feared as the prince’s loyal hound.

However, on his very first day, he stumbles upon a shocking secret—Idris and Crown Prince Laurent are lovers. When confronted by the prince, Zigrien impulsively lies, claiming that he is in love with Idris.

Intrigued, Laurent offers a twisted proposition: “I’ll give you the chance to hold the one you love for a night. Get drunk—right here.” Bound by duty and circumstance, Zigrien is swept into a dangerous game of power, deception, and forbidden desire. But where will this treacherous entanglement lead?