So long story short, my father lives on the other side of the country with my step-mom and my half-siblings. Because they haven't really been a major part of my life, it's never really crossed my mind that I should come out to them. But meh, the appropriate time came up, so I just went for it. Things went well. Woop.
Congratulations! It's still an important step, nonetheless, and it's great that things turned out well.