Bill reveals to Sam that when Sam was a baby, he left Erica and she waited six months for him and when he came back, she accepted him and he promised that if she ever left him, he'd give her a second chance.
She accepted. This is what Bill reveals to Sam. He'd give her a second chance. She ever left him. Him and he promised this. He left Erica and she waited six months for him and when he came back. Sam was a baby.