I admit I did not search the entire thread for the information, so please forgive me if I missed the answer.
To those who wear a chastity bra, is the bra connected to the belt by means of chains? If not, is there any chance you might be able to somehow slide it up to get out? What cup size do you have? (I know, the latter is not a polite question but I guess important when it comes to sliding up a bra or not.