News about my estranged father

I received a message from an uncle last night about my estranged father who ai haven't seen in going on 20 yrs. The story about my father is that mom and dad never lived together even though they were legally married for about 20 yrs. We were always moving around upon his command. My dad would visit us a few times a year, usually without prior notification. Anyway, my dad had several mistresses on the side and when my mom left my dad for good (then legally divorced him) he married one of the mistresses he kept around pretty much during their whole marriage. I think he even told my older brother or one of my uncles that he never loved my mom and always loved "her", always wanted to marry "her" all along. Anyway, my uncle sent me a message asking me if I heard the news that my father's "wife" had passed away. I don't even know how to feel or respond to that. How is a person supposed to feel? What is the proper thing to say to that? Do people in the family expect me to feel sorry for him? Or send my condolences that his "wife" died? I've always harbored anger towards my father growing up for not "manning up" to his responsibilities as a husband and father.... instead he was always running around to God only knew where with who knows. I told my uncle it was a "sad thing. 1st wife divorced, 2nd wife in the ground." I guess he is a lonely man. That's what happens to people who don't take care of their responsibilities. They end up alone.