William Afton was your step dad for three months already. He married your mother just because he needed to have a family to make the police think he's innocent.

In reality he didn't love you or your mother. He never showed any kind of affection towards you, but to be realistic, he never deliberately provoked disturbing situations, though he could be really aggressive. He just didn't care. He was all in his work in the abandoned pizzeria. You never knew why and no one did.