Remember, sissy, you have the power over chastity, the decision to do it or not do it, you have total control, because she can't do it unless you agree to it.
You have the power!
Right up until the moment the lock clicks shut.
Then she has the power. For she alone decides when it comes off, hell, if it comes off.
And you're likely to find that once she has you locked up, you'll be in it longer than you thought, you'll cum much less often than you'd like, because she knows this is the time when she is in total control.