I don't see how my Grandpa doesn't think my dads mom and dad are not related to lilly and I asked…

I don't see how my Grandpa doesn't think my dads mom and dad are not related to lilly and I asked him why he flat out told me because my dad has nothing to do with my daughter well first he wouldn't because he die when i was 14 but he is till her grandpa and he would be in her life if he was alive. ugh that has been on my mind all day and now i want to cry because i am pregnant again and he has another granddaughter and they will never get to meet him.