Worthy Promises by Jessamyn Kingley

Duke Argent Worthington D’Vairedraconis knows loneliness. For a century, his father confined him in a rambling old home. Decades have passed since he left his father’s court, and Worth has blossomed under the D’Vaire roof. But scars remain. Worth abhors the quiet and hates being alone. Although he once questioned Fate’s methods, he now yearns wholeheartedly for the other half of his soul.
At nineteen, Oliver Toivonen is handed the reins of his father’s fortune—or lack thereof. His parents are obsessed with wealth, prestige, and making the right social connections. They blame Oliver, not their lavish spending, when he must sell off the estate. Over a century and a half later, his folks are killed in a car accident and Oliver is left to raise the seven-year-old brother he barely knows.
In an expansive garden in the middle of Las Vegas, Worth and Oliver meet. Sparks fly immediately, and their beasts are ready to pursue each other relentlessly. Oliver must be pragmatic for his brother’s sake. But he is unwilling to ignore his heart. As Worth and Oliver negotiate their future, Fate tosses a few surprises at the D’Vaires. Oliver and Worth must make sure nothing gets in their way.