Size is something i am yet to perfect. i have bought 6 different devices in the last year, a rubber one was the start but that wasnt good enough as i could easily get out. Then i bought a couple of metal cages. Much better as they feel secure. I wore one for a couple of weeks that was a little too big, then i bought one that was too small. Go to a plumbing ship and buy a 40mm Washer 45mm and 50mm. Wear them for a few hours and see which one is tight enough but not too tight. Then i think the cage ideally you want it so there is a little room for growth but not too much. So its a snug fit when soft.
Strict is entirely up to you two, play with it for a few days, then slightly longer. But you gotta make sure she enjoys it and that she doesn’t mind daily teasing. If she just leaves you in it will start to feel that it was the wrong thing. Its a journey you embark on together and discussing it is very important.
Enjoy it, i know i do.
What a great idea, buying plumbing washers (I assume they are those rubber ring things) and trying out sizes! Our other tip is buy a CB6000S first as that has 25 different size combinations and use that to figure out what works for you.
We’d disagree on the sizing though, a little growth is fine for daytime wear but you want it pretty snug to stop night time erections from being able to ‘take off’ – so smaller is definitely better.