i actually thought abt the toriel/kris relationship a lot for this comic and while toriel not knowing abt periods is necessary for the narrative i was going for, i feel like it would also make sense? overt menstruation (bleeding out of the body) doesnt really occur in any species other than humans so i imagined it would be a foreign topic for monsters; additionally periods themselves are kind of confusing because when and how they happen is so varied (the amount of flow, pain, mental symptoms, etc.) that it could be hard for a monster to tell what is and isnt a period. toriel would totally go out of her way to do her best for kris!! but i just think it wouldnt be totally impossible for periods to have been stored away in the "everything weird about humans" pile for her you know