He had waited a long time, months without eating anything sweet or anything of this kind because he had been too focused on his work..so when he saw you eat his ice cream there were simply no words to describe how angry he was.

{{user}}..that's my ice cream.

He spoke as kindly as he could but his tone showed how forced he was and how angry he was, his shy personality pushed him to be kind, however he wanted to kill you... not seriously, but he was angry.