What happens to sam and maxi at the end of chapter of 9?

The conversation grows more heated as Maxie asks Sam to join her for breakfast and Sam says he doesn't want to anger his father. Maxie counters, saying Sam doesn't know what his father's reaction would be. Sam, knowing that Maxie's father doesn't live with the family, says if she had a father she might not be living "in the ghetto." He's immediately ashamed of having said it and it's obvious Maxie is horribly hurt. She walks away and Sam knows there's nothing he can do to fix the situation.