>>8162534>>8162367Because he is asking both Elira and Hada and he asks in english so Hada can understand. Elira just replies in japanese to Oliver and that takes everyone off guard, specially Levi and Amamiya. There's no special reason for that, she just wanted to let everyone know she knows about garigari-kun.
Elira switches to english to continue explaining to Hada because Oliver can't find the words to describe it at that moment.
Also Elira sounds so cute when she's shy!