Okay... what's going on here? Without translation it seems like it may be related to the raised by a witch thing that was popular for a while, but some related images on twitter showed the boy watching the witch dragging a bloody corpse while she was in a monstrous form.
The artist has been making a fair amount of horror stuff (their recent Kemono Friends image series), so... I don't know if it's tears of "this is the nicest I've ever been treated" or "oh no I've been tricked into cannibalism"