brosequartz:

queerandgrumpy:

headcanon that since the slytherin common room is under the lake there’s a room where the walls and ceiling are glass and you can just see into the lake like an aquarium

headcanon that when this was first done the mermaids got really aggressive and hateful about it and started ramming the glass but since it was magic this just caused them injuries

until a deaf/hoh slytherin started to teach them sign language and it took a long time bit by the time they left hogwarts they and the rest of the house were communicating with the mermaids and on good terms

eventually it becomes a part of slytherin house culture you’re a slytherin you know sign language because if you don’t chat with the mermaids they get grumpy

this helps a lot of deaf/hoh students

this also gives slytherin the best grades of any house on all aquatic magical studies

the mermaids give terrible dating advice do not trust them