@M2 It isn't necessarily wrong. It would feel very wrong to fall in love with someone who adopted you. If you treat them like a child and they are acting as your parent then obviously even once hes grown shed still be treating him like a son?
It's hard for a kid to understand love and so far it seems shes literally the only female hes been around? So his confusion makes sense. At least he understands the feeling he thinks he feels is wrong.