@Kaldrak
Its a different case and different time. Neither of them locked out.
1. Fake arai asked fennec to open the door cause she lost the keys. Fennec played with fake arai by questioning her.
2. Fake fennec asked arai to open the door cause she forget her key. arai quickly disbelief it by knowing real fennec never lost her key.
I think the anomaly is pretending to be your friend/roommate and asked to open the door. and the joke was how 2 of them deny this anomaly.