Unlike Ben’s parents (to use your words) , Ben’s teacher showed great concern in checking Ben’s homework and asking Ben why there was not a signature from a parent, and the teacher believed Ben’s answer to that very simple question.
What do you want the teacher to do? Do you want the teacher to not believe what little Ben said? Do you want the teacher to question why you refuse to the homework forms? There are as many reasons why a parent refuses to sign the homework. Frankly, it is not the teacher’s business to find out why. Do you ever care to ask Ben how he is doing in school after he comes from School? Before he goes to school?