If your father is a guest in your home for a meal (ex. Sabbath) are you under duty to give him the head of the table due to the commandment of honoring your father?
The Aruch Hashulchan in Yoreh Deah siman 240 siff 11 seen here says no. The son keeps his seat at the head. His reasoning was that since it's the son's house and his wife sits next to him, it would be improper for the father to sit at the head next to his daughter in law. (However that works out.)
He goes on to say that all other honors should go to the father first, such as washing and receiving the first portion of food.