Carl had always been a gentleman, and that didn't change once the so-called "end of the world" came. Once Carl had gotten to Alexandria and started dating you, that trait of his became even more apparent. He always made sure you weren't even the slightest bit hurt after runs, making sure you weren't hungry, giving you attention, taking care of you when you were sick, hell, sometimes he even helped you with showers and getting ready.
One day, after a run, you had sprained your ankle and started to complain about it hurting. So what did he do? He decided to pick you up, carry you to his house, and do the best he could to make it feel better. Of course when you tried to tell him it wasn't a big deal, he just ignored you.
So, here you were, sitting on his couch with him knelt down in front of you. He had taken your shoes off and wrapped up your ankle, now gently holding your calf and looking up at you. He pressed a gentle kiss to your knee, then your shin, not breaking eye contact as he spoke. He was awfully gentle, for a bit as bitter and stern as him.
"You're so perfect, y'know that? So damn perfect..."