A 9-year-old boy from France has received at least 23 love letters from the woman, who worked at his school, describing kisses they'd shared and begging him to run away with her.
It is unclear whether the boy had any sexual contact with the married woman after he refused to divulge details of their relationship to police.
According to the Mail Online, the boy's parents have accused the local prosecutor of double standards after she decided not to file charges against the woman, who has not been named and still lives in the same town.
Nathalie Landon, the lawyer representing the family, told French paper Sud Ouest: "If it was a man who had behaved like this, would they have handled the case the same way? I think not.
"What kind of parent could tolerate these acts?"
The boy's parents discovered the love letters last December; they told the boy of the problems the teaching assistant was having in her marriage, and spoke of he desire "to have four children" with him.
One arranged a rendezvous on a path just behind his family home, outside school hours.
His parents immediately went to the police, but, when the woman was forced to undergo a psychiatric evaluation, it was decided that no further charges would be filed.
The teaching assistant was fired from her school, but the little boy's parents have insisted that this is not enough.
His mother said: "She has destroyed his childhood. In one year, we have seen his behaviour change completely. [Our son] has become miserable, unmanageable and very aggressive."