Desmond felt guilty that he was relying on Leonor so much to take his stress away.
When he wasn't focused on the strenuous task of convincing all the highest ranked in Castille that they shouldn't blindly murder the rest of the Eirenguardians, he was thinking of her.
She felt like the only highlight of his day as he listened to people callously talk about people who shared the same blood as him being worthy of murder if they made the first blow. As if their responses to the brutality of their people weren't a fair result of Castille's war crimes.
He could tell King Stephano knew exactly how he was feeling and the monarch tried to be objective despite it being uncharacteristic that the King of Castille cared about the lives of those from an entirely different kingdom and certainly not loyal to him.