Elderly people may have various medical conditions that causes them to not process/filter information the way they could in the past. When one of our elderly relatives/parents/friends wants to talk about some inappropriate topic, we usually just let them know we don't need all of those details and move the conversation to some other subject. Aging can bring about all sorts of issues and we find it best to gently move them to some other topic since they probably don't grasp what they saying isn't an appropriate conversation topic.

4 years from now, I will have to make a point of telling this to some of my customers. (I manage a warranty department and some people are monsters.)
