Jason didn't have the words to express to the crown prince that it was never a game. He cared for Davion from the bottom of his heart, he was just not patient and that is how they ended up where they were.
Hearing the confession that he had always wanted to hear from the man broke his heart. Recalking his words and how he threw the engagement ring at the prince made him freeze.
Words and actions were irreversible, he let out what he wanted without minding if his words will hurt the man. And true to that, his words cut through the crown prince's mask forcing him to pour his heart out.
It was unfortunate. Despite all the novels that he had read, he was terrible at love. Love was patient, kind and selfless. But he had neither of this qualities when it came to his own love.