At that time, any good relationship Duke Bastella have with King Teriza was broken. With a grieving heart, Duke Bastella left the castle. He doesn't want to stay there anymore. The duke also doesn't want to see the dead body of the woman he loves the most.
At the queen's funeral, Duke Bastella did not even show up. He stayed inside his mansion and refused to see other people. Everyone who knows him is aware that Duke Bastella is closed with their queen. They are thinking that the duke is grieving for the loss of his precious friend and maybe a person he treats as special.
No one suspected that Duke Bastella has a feeling for their queen. He is really good at concealing his true emotions to other people. The duke doesn't want the people to see him as a person who has a weakness in his heart.