Thank! Actually that is part of the mechanic. When you are locked and at max arousal your fetish skill rises twice as fast but if you are in this state for too long you get the penalty that you are too frustrated and cant work, etc. The only way to fix it is to be let out of the chastity and have an orgasm. The length that you can stay at max arousal and not get frustrated will rise as the chastity level rises in later chapters. I am still finetuning how long should the length of the bonus period should be at each level.