Hello SPHCouple!
Welcome to the forum!
Very good. Your woman should not let you off the hook in that regard.
Hm.... well.... here's one. I suggest always addressing your woman with great respect. For instance, if her name is "Janice," always address her as Ms. Janice, or Ms. Janice Ma'am, or Ma'am (as in, "Yes, Ma'am"), or Queen Janice, or Princess Janice. (Ask her what she prefers.) I also suggest your woman always address you using term emphasizing the diminutive size of your endowment, such as: Teeny Weenie, or Pencil Prick, or Bitsy Balls, or Blueberry Balls, or (if your name is, say, "John," your woman might also address you as cuckold-in-waiting John, or cuck-to-be John.
That's OK. It sounds like your sexy woman is moving in the right direction.
Excellent. Here's another idea, Ms. SPHCouple. I strongly recommend ordering a chastity cage (i.e., a cock cage) for your man, locking him in it, and becoming his sole key-holder. See, for instance:
Mature Metal
IN THE BEGINNING - Steelwerks Extreme
Chastity Belts and Chastity Devices by Lori
Male chastity cage - HolyTrainer : Size and specifications, pictures & videos
(If you google male chastity devices, you'll see there are quite a few choices available.) There seems to be some agreement among the cuckolds on this forum whose wives keep them locked in cock cages that metal cages are superior to plastic. Also, more than one cuckold has found the "HolyTrainer" (which is not metal, but neither is it plastic) is secure and comfortable for long-term wear — which, of course, is important.
As one experienced cuckoldress put it, in a word of advice to married women (elsewhere on the web): "If you keep your husband locked in a chastity device, cuckolding will follow like night follows day."
Also, it will open all manner of additional possibilities for small-pens humiliation. For instance, you could require your man to drop his pants every day so you can verify he hasn't somehow wiggled out of it. Then, you can giggle (or insult his diminutive penis in some way) whenever you see it.
In addition, once your man is cock-caged, you could consider acquiring a strap-on dildo, in order to fuck him up his ass (while he's still wearing his cock cage) whenever you feel like it. This would probably result in some sexual satisfaction for him, from stimulation of his prostate, while also providing you with an orgasm (from stimulation of your clit, especially if it's a vibrating strap-on). And, together with cock-caging your man, it would unambiguously establish you as the dominant partner in your relationship, which will definitely be an advantage when it comes to transforming your man to your (for real) cuckold.
Good luck with this! It sounds like you're on your way, Ms. SPHCouple.