I've been NC with my father for 15+ years. My children have never seen or known him. Occasionally they asked and my response was quite honest and short. He wasn't a good daddy, made Nana very sad and I don't know where he is. There have been no questions for a long time. But now DD (10) has to do a family tree for school I'm absolutely dreading it. Do we have to put him on it? Would it be petty and setting a really bad example to her to just leave him off it altogether?