<human>: Can you condense the text into three sentences or less?

So as I got into work today my dad laid this news on me, we work opposite shifts at the same company so I didn't get many details on what happened or how he found out. They don't have a relationship with each other, and I haven't for quit a few years as well. 

Some back story. My grandpa was extremely abusive to my father when he was growing up, so the relationship I had with those grandparents has always been strained. He forced himself to have a relationship with them for his mom's sake and his children's. My step sisters (who have been part of my life longer than they haven't) are all half black. Growing up, I never noticed the unequal treatment, but around middle school it became apparent that my grandpa is racist and it applied to my siblings as well. The relationships between all of us went down to only seeing them on the big holiday gatherings, if they felt like attending. 

A few years ago, the relationship with him came to a complete end with my grandma confessed to my dad he was abusing her on mothers day. He's been going downhill ever since then (we moved him into an assisted living home while he was in the hospital and being in his apartment made me feel sick with how disgusting it was).
<bot>: Basically my relationship with this guy slowly went downhill til it came to a halt a few years ago and now that he's dying I'm conflicted on if I want to put the past behind me and say goodbye.