The Chastity Belt Experiment, Book 0: Proof of Concept

When Liliana Reyes does something, she does it right. If her friend and lab partner Michael Pagano wants to find out what it's like to be locked in a chastity belt when someone else has the keys, well, he's going to learn. (This is a prequel/introduction to The Chastity Belt Experiment series.)

Michael has been working on developing a chastity belt for himself and has gotten to the point where he's giving it trial runs. When Liliana points out that it's not a real trial run unless someone else has the keys, he can't argue with that. But when he hands over the keys, she uses every bit of her considerable ingenuity to ensure that it's a good trial run.