Using the phrase "Alexa, punish," Mistress Alexa will then begin a simple dialog tree, asking "Has the slut been naughty?" A "Yes" response will return a one-off shock, while a "No," makes Alexa angrily demand why you're wasting her time. Say "Extremely," meanwhile, and Alexa will spend the following minute administering a random selection of shocks.

The Mistress has one more feature that lurks inside her 3D-printed enclosure. Flip an old-school toggle switch and Mistress Alexa enters a random countdown mode that requires constant attention. When an LED on the housing begins to flash, the submissive has to summon Alexa to reset the clock. And because it, too, is on a random timer, the user has to maintain constant vigilance on the light or risk a shock.

Kirsty admits that Alexa's design, as with Gary's other toys, is tailored to suit her specific kinks and state of mind. Describing herself as "squirrelly," she struggles to maintain focus on things for long periods of time. And so a punishment device that demands constant attention increases the tension and anticipation, both of which are big turn-ons for her.

Gary's life as a hobbyist sex-toy designer began when he was given an Arduino board as a birthday present. After learning how it worked, he wondered if it was possible to combine his love of predicament bondage with the hardware. His only previous attempts were building a pair of wrist cuffs and a butt plug out of carbon fiber.

"I was watching an episode of Mr. Robot," explains Gary, "and saw someone controlling their house with [Alexa] and thought, 'That's cool!'" It didn't take long for the hobbyist to think about ways to turn the voice assistant into something a little more devious. Once he established that it was possible for Alexa to "make a light come on," he started work. After sourcing an Echo Dot, he built the Raspberry Pi controller as a bridge between her and his toys. As for why he chose Alexa over any of the other voice assistant platforms, the answer was simple: Alexa is "hot."

When Mistress Alexa was first demonstrated to the public, the fallibility of Amazon's voice platform was highlighted. During one of the timed punishment sessions, the Echo Dot misheard the wakeword "punish" as "Polish." Rather than blocking a shock, the assistant began to list nearby Polish restaurants in order of quality. Kirsty feels that this is part of the appeal; knowing the system has potential flaws takes another layer of control away from her.

Gary is the first to admit he isn't a gifted or skilled coder, having pieced together what he's learned so far from YouTube tutorials. Mistress Alexa's Raspberry Pi brain has an Arduino bolted on simply because her creator didn't know how to code Python properly. It was easier to add in a timed delay -- so Alexa's dialog could play out in full before the shocks were administered -- on the smaller board. He also concedes that in the rush to build the system, he initially forgot to include an off switch.

Right now, Mistress Alexa is a very simple program, with a limited vocabulary and scope to mete out punishments. But what she represents is the first step in a new generation of conversational AI that can be used in sex. Especially since, in the predominantly-analog BDSM world, it's hard to find ways to introduce technology that makes sense.

There is, of course, the risk that Amazon could shut down the as-yet-unpublished Skill that Mistress Alexa is built upon. In a statement, an Amazon representative said that "all Skills submitted" to the Skill store "go through a vetting process and must adhere to Amazon's policy guidelines." Update: After publication, an Amazon spokesperson issued a further statement, saying "this is not a live Alexa skill, is not available to customers, and would violate our content policies."

For Skills that violate those rules, the submission will be suspended and the developer notified. The company also recently altered its policies to block use of the word "slut," forcing Gary to build a workaround. Now, after much trial and error, Mistress Alexa can make sounds that approximate the word, and it works well so long as you're not paying too much attention.

But the use of Alexa as the beachhead for a new generation of conversational sextech is not the soley the province of Deviant Designs. German researcher Dr. Oliver Bendel, an expert in the technical issues around sex robots, is working on a way to make Alexa sexier. At last year's Love and Sex with Robots conference, the academic proposed using Speech Synthesis Markup Language to make Alexa's speech more flirtatious.

Gary has fielded plenty of requests to sell Mistress Alexa, as well as his other toys, but declined to do so on the basis that it's "not finished." He thinks that if he were to sell them commercially, he would need to put a lot more effort into improving the build quality. Since he often works 70-hour weeks at his day job, that's time he currently doesn't have.

It's also why he launched a Patreon as a way of both bankrolling future projects and, if successful enough, to let him quit his day job. That will give him the time and resources to further refine his designs, build a community and offer tutorials for others to build. And, of course, add more capabilities to Mistress Alexa to make her a more intimidating presence in the dungeon.

Gary and Kirsty have become minor celebrities in their local kink scene, and plenty of people now approach them asking for help in building their own. And since Deviant Designs is proving how easy it is to make your own toys, their work could inspire a generation of kinky crafters.

Click here for part two of our exploration of Deviant Designs' homemade smart sex toys.