Chastity and orgasm denial discussion

I’m fairly new to the world of chastity. Since early April 2014, I’ve been wearing my cage, and both my Keyholder (KH) and I are having a great time. Being more of a serving husband has strengthened our marriage even further. Typically, I go about seven to ten days without release before she lets me orgasm for her service, after which I’m locked back up within an hour. I find it straightforward to bring her to climax multiple times while holding mine in. (It might sound boastful, but I mean it.) My goal is simply not to come; I’d rather stay teetering on the edge and then be left alone. Yet, my Keyholder insists that I release when she orders it, which happens just a few strokes later. I’ve told her clearly that I don’t want to climax, but I get the feeling she doubts me. Can I persuade her without resorting to ‘Topping from the Bottom’? Or should I simply obey as commanded? I also sense she’s deeper into her Keyholder role than she admits. For example, while shopping for holiday attire today, she pointed out swim shorts and T-shirts. When I mentioned needing to be careful about which style of swimsuit bottoms I chose because they might reveal my state when wet, she retorted, “What makes you think you’ll still be locked?” and left it at that. To the untrained eye, this vanilla dynamic might seem dull, but we are progressing steadily. I am pulling against the leash (just kidding; we don’t actually own one). Your thoughts would be welcome.