So many fun thoughts to consider, I really must keep more of an eye on our conversations, so I don't take so long to reply *blush*
For me, part of the thinking about "trapping" Jack was mental, as much as practical. I see and completely agree with your point about "running where?", but I simply had not thought of this from this point of view. I started with a much smaller scale and focus here. If Jack is passing as a convincing and attractive woman, then "he" can go out for a night, get drinks paid for, let someone keep "her" company for a meal...
It gives a sense of confidence and independent existence. I have met several "ladies" where the first clue you have that they are not quite what they seem is when you discover the erection going on between their legs. Perhaps just the circles I move in, but I am quite used to seeing a confident female viewed as a desirable and respected person to talk to and interact with...
I think, in very vague terms, what is happening here is that I am thinking of "you", the author, who I see as a mind with real drive and focus, as the "female role model" here. So I then think of Shelia and the married Jackie as similar strong and capable women. Yes, married Jackie wants a stronger man in her life, but she has set about doing this with strength, purpose and will!
But the other side, as Jack "fails" as a man, we want this submission to continue, rather than to give him confidence and power as a woman, we want Jack to see being a woman as a lesser role, that he also fails at, but also all that he is suitable for and good for.
Cosmetic surgery seems overkill for Jack, but a good pair of fake breasts (breast forms) would do wonders for helping her to fill out her outfits, look the role, and encourage the whole talking to the tits, not my face, side of being a female who is looked down upon by men.
Having Sheila pass Jack off to someone else to babysit while she has to travel fits very well with the wicked and wilful woman I find myself picturing her as being.
I never saw a need to keep Jack from competing with Jim, so this concept is quite a surprise for me. I see the logic, so I have been wondering why I was not thinking in these terms. For me, Jim is never going to be challenged by a "male Jack" simply because Jim is the dominant in this relationship. For now, at least, I see Jim as the dominant in a long running but consensual scene. So long as Jack does not safe word out and remains safely locked away then he is no threat, almost by definition. To my mind, the only "threat" to the situation could come from Jackie, the wife, not being so accepting of his advances. But this is being taken care of by treating her with the ongoing mixture of respect, gifts, and forcefulness that he is already using.
For Jackie the rules are changing, and with time the change will be felt by both men. For Jackie this is no longer a scene, Jack has burned to many bridges, has crossed to many lines, and finally, instead of feeling in a put upon position in her marriage, Jackie is discovering what it is like when things are much more about anticipating and fulfilling HER wishes and desires...
Oh yes, someone has to be at fault and blamed, and punished, for what happened to Shelia's marriage, and its oh so human that it won't be her. So Jack is the perfect one to blame, and she has various reasons to hold him fully responsible.
Piercings as a marker make sense on several fronts, but I find myself strongly against Jackie having "name tag" nipple piercings. I am not sure why I am so firmly against this, but perhaps the best way to describe it that I can think of is that it is "tacky", cheap and basic, and just does not fit with how I see Jim treating her.
Having said that, a small wrist or ankle chain that she cannot remove, that has the same message, but also functions as both general purpose jewellery and a subtle "collar" would fit rather well
The original idea was as much about getting Jackie to the point of agreeing to having Jack pierced as it was about anything else, while also providing an amusing echo / parallel
I see the logic, and quite a lot of the emotional power of the pregnancy, of Jackie ending up pregnant, but I really struggle to see how this can be done without disrupting the fun and erotic nature of the story... but, since we are thinking of coming at this from a different point of view... there is a lot to be said for Jackie rubbing Jack's nose it it, describing and telling him about the wild, passionate and spontaneous sex she has with Jim (made up, since no need to share the real events with Jack?), and pointing out how helpful it was him having his sperm checked all those years ago, since Jackie knows that she is not fertile, so they never have to pause in their passion to worry about condoms...
Perhaps a good way of making and driving home the point that she has known for some time that Jack was actually the one with the fertility problem, and that she came to terms with this years ago, but is now discovering that she still has a fair bit of buried bitterness and spite over his lies?
I love the evil thinking of glue that Jack applies to the lock himself, but there is a logical flaw here. Glue will build up and collect inside the mechanism, so it won't be long before Jack knows it is glue, since only a few drops will fill up a small padlock hole. But something else he added to the lock, perhaps something that happened to eat away at the mechanism instead... You can keep on applying that without it ever filling up...
But it also opens the door to Jack retrieving his hidden key and finding it does not work, since the inside of the padlock is now loose, with some of the components dissolved away over time. Again though, how can he bring up this discovery without admitting to keeping and trying to use the spare key?
I like the idea of having Jim and Jackie move, so they can be more open about living as a couple, but on the flip side, they can be open without judgement, but it avoids the constant embarrassment and reminders for Jack from his old neighbours, his old neighbourhood, of all that he has given up and all that is now Jim's instead.
As for your life and companion, the number of people I have met over the years who think, and are quite sure that the life of the one in charge is all roses, being waited on hand and foot, all of the attention yet none of the responsibility and work... *rude snort* The only ones who get any of that are the shallow assholes and it never lasts for them.
Making this fun and erotic for both of you is the key. Have you explored pampering? This is a random idea, but for farming out, find and send your man on a course on giving a full body massage. This is a skill that will take a fair bit of time and effort to really learn, and it is a skill that should exist specifically to be lavished on you, the key holder, the one you want to impress, the one you want to reward...
If not massage then some other valuable and you focused skill? Training is a form of farming out, if you can find skills you would enjoy him learning. Just a thought, and it has to be very focused on the two of you, otherwise it stops being fun, but something like this might just work