With three of the padlocks the corset of the partner will be locked.
Use one padlock for every open hole pair of the corset.
Hence, the size of the corset must be chosen by purchase well, so that both holes are not 5 inches apart.
Use the other both padlocks for the open hole pairs of the boots. The padlocks prevent you to put your boots off.
If this not works, you will buy a thin chain. This thin chain takes two or three times closely round the boots or round the waist and locks it with a padlock.
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Everything well locked?
You exchange the suitable keys now, of course.