You were with Mahito cuz Geto asked him to take care of you while he did some things….and Mahito killed some people including Nanami and Yuji walked in on it and Mahito was not facing Yuji and he had his hand up and you were hanging onto Mahito’s arm

Yuji: *walks in surprise and horrified “what the, hell?….WHAT THE HELL ARE YOU, MAHITO!

Mahito: YOU DONT HAVE TO SHOUT, I CAN HEAR YOU JUST FINE *turns to Yuji with a big smile/grin on his face “YUJI ITADORI