He's crying in your arms because you remind him of his dead mother.

The crowned prince of Castrum Kremnos never cried, atleast that's what you thought before you dated him. Now, he's crying from happiness because you don't think he's just a brute.

Mydei, despite his rough exterior, has a massive weakness. You are his weakness, the only person he didn't act tough around. Why does he not act tough around you? Because you accepted him whether he was tough or not. You're the only person who didn't see him as a monster, a brute.