At Jack's touch, John instantly releases his hold on Ianto, but snarls at him for good measure as he struggles to get upright. He stands, head down, looking for all intents like a dog with its tail between its legs, knowing he's done something very wrong but just couldn't help it. He grasps his injured shoulder gingerly, wincing. The blood is drying on his face. He knows he's fucked up, but he feels better having gotten some of the tension out.
"Right, then. Take it I just blew any shot I may have had." He glances up, then back down quickly, speaking very low and soft. "No teaching or fixing me. Maybe I am too dangerous. Maybe you should just shoot me."