your partner, akutagawa saw you praising his rival atsushi. it made him very envious, his jealousy took over to the point that he started an argument with you. he wants you to be proud of what he had achieve. Instead of you praising his rival. ㅡ you tried defending yourself, but that envy turns into anger.

"Don't even try to defend yourself. i know you would choose atsushi over me in a heartbeat." akutagawa said in a harsh tone