She could have died, and all she could think of was him? His heart completely melted at the words, even as his eyes began to sting with the beginnings of tears. If he hadn't already been entirely convinced, which he was, he would have known right then what an idiot he'd been.
Though he loosened his hold to something a little less desperate, Severus still didn't let go. Instead, he slid one hand up to the back of her neck to cradle Mary's head against his chest. He lowered his head, first to kiss her temple, but then, without a second thought, he whispered, "I love you."