So, I recently learned through DNA results that my dad is not my real dad. Unfortunately, lately with DNA results, this is most likely not unique but there are some complicating relationships in my situation that I don't know what to do with - I will explain below so bear with me.

My parents had divorced when I was about 4 years old. The divorce wasn't necessarily "messy" and they had agreed for my dad to parent me every weekend - which was the case for almost every weekend until about 16 when I started working.

My mom remarried a couple years after to a man who I had known as a family friend and he had a daughter who was my friend. We became a family when I was about 6. We welcomed my second sister shortly after.

I'd say that there were a "normal" level of complication with a family with a step dad, step sister, half sister and going away to see my dad every weekend.

My step father passed away when I was in my early 20s from cancer but we had a good relationship.

If you haven't guessed yet, the DNA results informed me that the man I knew as my step father is actually my biological father. I have struggled with this for many reasons and could ask for advice on any number of complications but what I really need advice on is how I handle telling or not telling 2 important people in my life.

1 - My dad. The one I grew up believing as my biological father but really isn't The one that is still alive. I have not told him. I'm not sure if I should. Would he see me different? Does he have suspicions? Does he already know? Would he regret not having another child? Will he hate me? Too many questions to list.

2 - My "step" sister. The one I've known since day one. My best friend up until a few years ago. There is outside drama that I don't think is needed for context but she is a bit on the outskirts of the family. We are still close but not as close as we once were. But I believe she doesn't know this information. I wouldn't mind telling her and actually think it would be cool to know we are connected by more than just marriage but what makes it complicated is that her and I are only a couple months apart, so that means our dad cheated on her mom when she was pregnant. This news would be a pretty big impact if she were to find out.

Thank you for reading - I struggle because this news is eating me alive and I feel that telling these 2 people would ease my anxiety but could potentially derail their lives. So, my question is, should I tell my dad? Should I tell my sister?