my dad's dad who passed away last year might've not actually been his dad, but he loved him and took care of him regardless of a DNA test. my dad loved him very much regardless. and even if I saw him a handful of times when he was still alive, I was his grand kid. my "real" grandpa (on my mom's side) is a [censored] horrible man, he was physically abusive and basically every other horrible thing, he might be my grandpa 100% in the DNA department, he isn't my grandpa where it counts. I think at the end of the day, it's ok to not be blood related to someone, I think all that matters is love.