User.belongsToMany(House, { through: UserHouse });
House.belongsToMany(User, { through: UserHouse });
user.addHouse(house);
house.setUsers([user1, user2])
http://docs.sequelizejs.com/ da/latest/docs/associations/#belongs-to-many-associations http://docs.sequelizejs.com/en/ nyeste/api/associations/belongs-to-many/