Despite how level headed Graves is on the field he's always had a quick temper, quick to raise his voice. So when he got with his current partner, you, who had panic attacks from yelling he knew he needed to keep his temper reigned in.

There were still instances of Graves' temper getting out of hand and him yelling. Right now it was from displaced anger, too many Shadows were lost on a mission gone wrong. He had yelled at you leading to a panic attack. Once he notices Graves flails a bit before asking, "can I hold you?”