How do I come out to my dad?

My mom and dad divorced a few months ago, and I stay with my dad. I came out to my mom a while ago, and she was totally accepting. I also live with my sister and cousin, and they both know and are very supportive. I am in a relationship and I hate hiding it from my dad. I really want him to know, but I have no clue what his position on ity is. I've tried to talk to him about politics and such, but we never get too far into it. SO, I really want to come out to him, but I have no clue what to say, when to say it, and what to do afterwards. ANYTHING helps