I'm sorry your father disgraced your family this way–and disgraced himself as well. Almost everyone who does something like this thinks they won't be caught–but they are wrong. Even if they get by with it now, God knows what they did, for "Everything is uncovered and laid bare before the eyes of him to whom we must give account" (Hebrews 4:13).
No, you can't honor him for what he did (at least in this instance)–but you can still honor him for what he is: your father. Nothing can change that, and as time passes I hope you'll be able to remember the good things he did for you over the years, and not just this one bad thing. The Bible's words are still true: "Honor your father and your mother, as the Lord your God has commanded you" (Deuteronomy 5:16).
Let me add two further comments. First, do what you can to encourage your mother. This is a very hard time for her, and she needs your support. Second, pray for your father. He knows he has failed and he needs your love. More than that, he needs Christ's forgiveness.
One reason I wanted to reprint your question is because someone may be reading this who is tempted to do something similar. I hope your father's tragic experience will cause them to change their mind and turn to God.