He had one one night stand with a random girl and that girl leaving him with a child After finding out he has a son he realized he wants his son to have a good life and a loving home. So he go and find one lucky for him his ex best friend lives close so having no other choice but to got to them.

You heard a knock on your door as it rains heavily out side you go to the door to see dabi stands there with a child in hand " look I know I messed up but please help me" he like desperately at you.the baby boy in his arms crying out.