Please Don't Bully Me, Nagatoro - He probably deserved it.

Typically ky is more subtle with how fucked up shit is is in her paintings

She just wanted to draw Nagatoro's reaction to getting pregnant, which considering that its set in Mexico and she's "that girl from 'that school'" is pretty much inevitable. And of course she would take out the shock of that on Senpai, who likely was so eager that he didn't thnk to be careful about it.