When you are hopelessly locked up,
And those old memories, that old need, comes back, memories of what you once enjoyed,
And your need for sex, for penetration, pure raging animal lust, becomes unbearable...
The want, the need to feel Her body as She teases and torments you, grinds against your caged cock and the discomfort becomes more than you can stand...
Are you going to be a whiny bratty sub, begging for a release that you have not yet earned, and thereby earn a session of hard discipline?
Or will you tough it out, and live vicariously through Her lover, imagining yourself in his place as he satisfies her for you, relishing and worshipping his cock like a surrogate, as She wishes. Let his satisfaction become yours.
If you do the latter, the release you will earn will be so much more satisfying than any casual sex could ever be.