He needs some help from a teacher or guidance counselor.
Just ignore stuff like that.
Would this hurt or help my child?
Are you sure he's actively using it to masturbate or merely curious?
They are often just meant to make parenting as convenient as possible for the adults while relegating children to second class citizens in the household.
Do you have anyone at his school who you trust?
If he does, he needs more support and perhaps some therapy.
I was like a deer in the headlights staring at him, and I did not know what to say.