Responses
Short answer no. Longer answer you can scroll down but maybe spoilers.
Nothing sexual happens with the teacher and Dongchan. Unless I missed something while reading, but it’s confirmed later that nothing sexual happened between them and the teacher had turned him down (I’m pretty sure the teacher says something to Sunny about feeling bad for turning Dongchan down or smth).

Can someone.eone please tell me if this involves child grooming to the point of it getting sexual.?Just as a warning for myself, I don't really mind spoilers