I love the ending of this story. None of us will ever know for sure how long Thomas kept Alex and Oliver like that and what other punishments he gave them. But we can imagine.
You employed the "jumping back-and-forth in time"-feature really well. With it, you set the stage in the first chapter and you come back to that point later on. I was a bit sad though that you also used it to shorten the foot-sniffing part in the last chapter
![Wink ;)](./images/smilies/icon_e_wink.gif)
. The details in your story are nice, for example the speedos and ball gags that were colored alike. They help the reader to form a better picture in the mind.