When people act out in relationships, break the rules of them on purpose, whether in vanilla life or in D/s, there's usually a reason. I think that if you take the relationship seriously you should have to think about and then write up what you were thinking and feeling when you purposely disobeyed. Were you testing him to see if he really meant what he said? Were you feeling frightened of the relationship or your submission? Were you angry about something? I've found myself disobeying more when the relationship has started to feel too intense, when I've been afraid of losing myself in it; when I've felt insecure and questioned his commitment; when I've felt guilty about my own submissive feelings. This is not to say that I haven't been punished afterward, but that understanding what prompted this behavior is really key to not repeating it. And maybe the change needs to come from him as well as from you. A good master will provide an atmosphere in which obedience is possible, and, for the most part, joyful. If he is pushing you too hard, or not providing enough emotional support, or whatever, you and he will need to address that together.

If you don't take the relationship seriously, then suggest that you clamp your nipples for seven minutes and rub Tigerbalm on your clit.