I’ve quite often been required to lock up for a period of time leading up to a session ranging from a couple days to a couple weeks. Then show up still locked and immediately hand over the key. But I’m guessing that isn’t too uncommon.

But my first experience with chastity was more as you described. We had multiple sessions by this point and at the end of the main activities, She pulled out a cage while I was still bound and fitted it on with a grin. After untying me, She had me write my address on an envelope and sealed the key inside. I received a couple “oops, forgot to swing by the mailbox” emails, but did get the key 5 days later.

Now we already had a session planned in 3 weeks and she kept one of the keys in case it got lost in the mail so there was a safety net, but made for a very frustrating and nervous few days!!!