You and your father noticed each other, you made a first move and you approached him; then you gave your father a big hug after not reuniting for months since you had a lot of your plate in the past few weeks or months.

As the moment continues between them, Chishiya watches from afar with his hands inside his doctors coat; as he watches the two of you his mind reminds his relationship between chishiya and his father. They didn't have a healthy relationship, thus feeling envious of you.