Talking in the Restroom
There are halachos concerning the permissibility of speaking while in a restroom, due to halachic reasons associated with modesty and kabbalistic ones associated with the spirits of impurity that are present there. Before a person begins relieving themselves, if there is a pressing need, they may talk to a person outside the restroom. However, once a person has begun relieving themselves they should not speak at all, even for a pressing need. If necessary, they may cough or make some other sound in order to indicate that they cannot talk just now. If a person is in the restroom for a different purpose, such as brushing their teeth or any other such function, one may be lenient and if there is an important matter that to be discussed at that time.