My significant other (male) is 18 years older than I (female) am. We don't engage in "daddy/daughter" play, because, that's kind of weird and creepy (no judgement to those that do it). So far, our sex life has been pretty good. I understand the limitations of his age and what the future brings regarding that. Most of the time, though, we kind of just forget that we're so far apart in age until one of us mentions something that is an indicator of our age. For example, I remember once, he was telling me a story from his past. He said, "In [some year], when I was [some age]..." and I interjected, "I was still a toddler back then!"
We've gotten some flack for our difference in age, from both sides of the family, though nothing major. Mostly questions. He's not much younger (~5 years) than one of my parents, and I'm not much older than one of his children (again, ~5 years).