This was one of the things I was stressed the most about. My dad passed away when I was 8 years old, and my stepdad came into my life about a year and a half later (not as my mom's boyfriend, but eventually things went that way). We've been through a LOT in the last 15 years together, not always having a good relationship. I love him dearly, and still want to do a father daughter dance with him, but didn't feel like I could find anything fitting. They're all about dads not being around (which mine would've been if he could) or if you went the more traditional route, about him being there from day 1, which isn't true. I asked him about it and he suggested Rascal Flatts "My Wish for You" but that is what my FMIL picked for her and FH to dance to, and she is not the kind to share the spot light.
Today my mom suggested "Here Comes The Sun" by the Beatles and I started crying for so many reasons. He came into our life in some really dark times, even for him (going through a vicious divorce and losing custody of his daughter), and we got out of that darkness together. But also because my actual dad LOVED The Beatles and I remember him singing that song to me as a child. Something little that only my mom, siblings, and I will know, so as not to make it a sad moment, but still feel like my actual dad got to be there too (his photo will be on a charm on my ankle). I just wanted to share in case anyone in a similar position was still searching for a song.