One approach is to grant her privileges that would otherwise be unreasonable, but only when you're locked. This could be as simple as "She's in charge" or as specific as "he does all the cooking when locked".
Beyond that, vanilla partners usually have trouble with Masoch's Paradox: Us wanting things we don't like/liking things we don't want.
It might be worth explaining that your kink operates on a continuum from "Fun" through to "Fun to be Scared Of" and that therefore chastity can be both a torture and a punishment.
Once you have that established, two possibilities come to mind:
1. Adopt some elements of FLR. Ask her to set you targets with chastity penalties. These could be specific chores, or - perhaps better - personal improvement targets.
2. Connect your chastity to her orgasms. In our case it amuses Xena that her orgasms add penalty days to my chastity. However, you might want to work it the other way around and have so many of her orgasms required for you to earn one for yourself.
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