Barracks room lawyers are never popular. Sometimes it is better to think about the spirit of the law rather than the letter and apply a little common sense. Even if you are allowed to do something normally, for example, always be aware that that situation may change in the presence of your Master or when performing another task. You should always be able to ask permission if you think you are hitting a loophole (so, 'master, may I go to the toilet' when having sex is acceptable - he may say yes, he may say no but at least you do not get into trouble) and if you think enough ahead you can always pre-empt permission ('Master, while I am doing this task for you, what is the status of my other permissions? can I still go to the toilet/touch myself/cum/whatever?') so that you know exactly what is allowed.

This sort of preparation and thought is valued by a Master because it gives them cause to think about aspects of a situation which, maybe, they had not considered without looking like they are negligent of your needs. So, if you are not sure, ask.