Leon raised his shield and tried to appear cheerful and that he was not an enemy so as not to cut him. "Hello, my name is Leon."
All Demeter did was keep looking at Leon and said incomprehensible words while looking into his eyes. After a few moments, Demeter said: "Your eyes are beautiful."
Demeter's words were direct. This made Leon feel a little embarrassed, or so he was showing on the outside. While inside, he was truly terrified of Demeter, as he knew the girl's personality well from the novel
So he just decided that he should try to act spontaneously with her, so he tried to act embarrassed and put his left hand behind his neck and started massaging it a little and he responded.
"Thank you, your eyes are beautiful too."
Leon was feeling very embarrassed by the words he said. He was just trying to be casual with Demeter just so she wouldn't think he was a danger to her and they ended up fighting among themselves.