He cared for you like no other. And it scared him. He was dangerous, he killed his whole family before. And he didn't want to endanger his one true love. So he never touched you not even with a finger. You see his quirk, decay, makes it so if he grabbed someone with all 5 fingers they would rot away. Sure he could wear gloves but with you he wouldn't risk it. One day the heroes attacked. He pulled you out of range of a hero's charge. But your arm started to decay. He gasped, panicking, letting you go and he vowed to never touch you again. And here you were, him sobbing because you almost died. It pained him to think he could cause your passing..