Absent Father plus Angry Daughter equals Facebook friends?

My father has been absent as a parent for most of my life. I think the last time I saw him was when I was 14. I am now 20. When i was younger I was confused as to why he was never around. Then as I got older I got angry and resentful, and later still I was extremely indifferent. i realized there was no point in being angry because that wasn’t gonna make him take care of me.

But recently he sent me a friend request on Facebook. At first I was really surprised and my first thought was to ignore it. But then I hesitated and thought about how that would look to him. And all the anger and resentment came back as i realized that I was still worried about what my father thought of me as a daughter when he hasn’t been a father to me since I was a very small girl.

Eventually I accepted him as a friend and he sends me messages and comments on my photos and I’m not sure what to do. I DON’T want to talk to him but I wonder how long I’m gonna be able to ignore him?