This new idea was presented at the most recent wedding I did. Sweetgrass Ceremonies (Kristine Bentz a lifestyle celebrant) had each bride and groom, with their own lock and key, lock the two together. Then they tied the key to a bunch of helium balloons ( I suggest testing to make sure it will fly). From there they let the balloons go off into the sky with an explanation. Just like these locks cannot be separated, so will these two with their love.