n junior year of high school, my dad got remarried to the woman he’d cheated on my mom with several years prior. As an angsty teenager, I was none too thrilled with his new marriage and was honestly pretty cold towards her whenever we saw each other.
A year later, my dad was taking me to the airport on my way to college, and my stepmom took off work to meet us there and send me off with a care package. She hugged me and told me that she was proud of me, and when she stepped back, I saw that she had tears in her eyes.
It was at that moment that I realized that she wasn’t a bad person, even if she (and my dad) had done some bad things in the past. Our relationship improved dramatically after that, and now she’s like a second mother to me. © OldSaintNickCage / Reddit

Story 2: 

When I was 8 years old, my mom got married for the second time. I was very hostile toward my stepfather. He was a nice man, but the very thought of him taking Dad’s place drove me crazy. Mom was torn between us.
It wasn’t until I was 10 when everything changed. It happened when he came to school to defend me from the teacher. I started ignoring him less often and agreed to go for walks together a couple of times.
That same year, on his birthday, I made him a present for the first time: I gave him an envelope with a card where I wrote, “Will you adopt me?” It was the first time I saw a grown man crying while tucked into the shoulder of a little girl. A month later, he became my dad, and after that my daddy. © Not everyone will understand / VK

Story 3: 

I have always told my children, “Just because I’m not your father doesn’t make you any less my children.” I was never able to have offspring of my own, but my grandpa grew up in an orphanage. He always said the best part of a family has nothing to do with blood. © BB64 / Reddit