The Ruby Dragon Prince by MM Farmer

Once upon a time, in an enchanted kingdom of captive omega princes and jeweled dragon alpha princes….

Tovey
Even though my brothers and I are of royal blood, our lives have been made miserable by our father the king. He has locked us in the castle and gives our heats to wicked nobles to secure their loyalty and their gold or ogres of his choosing. It is a life of sadness and desperation that I would do anything to escape.
Until a secret passage is discovered in our bedroom that takes us to a glittering world of magic and desire…

Rufus
I knew that the clever, beautiful omega that stumbled into that springtime ball was destined to be mine from the moment I saw him. We danced, we flirted, then he foolishly tried to leave. How could I not pursue him to win him back and make him mine in every way?
But my sweet omega prince has a greater evil pursuing him, and if I truly want to keep him, I might fight his demons for him and win.