Father In Law

When one gets divorced does he automatically stop calling his father in law his father in law?  What are the rules on this sort of thing?  When I introduce David Atwood to people I tell them he is my father in law. It would seem a bit weird to say he is my ex-father in law.  I don't know what the proper etiquette is here. To me it is no big deal and I have no problem telling people he is my father in law, he is.  He is a grandfather to my children, the father of their mother.  Anyway, my father in law came into town today.  He drove out from Alabama and arrived in Cedar this evening.  We met up with him for dinner at the Brick House and enjoyed sitting and talking and eating.  The boys sure were excited to see him.  Natty arrived a bit later as she was at a friends doing homework (on a Friday night of a long weekend, extra long? I'm not convinced that was all they were doing).  Anyway, she got there and we all enjoyed telling stories and having a good conversation.  I am glad he was able to come out and see the kids.  We will do some fun stuff tomorrow if the weather will work with us and on Sunday we will have dinner at the folks house and celebrate Andy's birthday finally.  He has been waiting a long time.  I thought he would forget about it, he has not.  It will be a glorious party I am sure.