When I was fourteen I was just about to come out as gay to my dad. He kept making jokes about me being gay, so I assumed he already knew about it. When I actually came out to him, he acted shocked. A few months ago when I was talking to him I found out that he just thought I was going through a phase. He still jokes a bit about my sexuality and I just don't know if he's accepted it or not.
Sometimes, people make jokes because they don't know how to express themselves. It has nothing to do with you. If your father didn't have a hunch you were gay, I can imagine his surprise. I wouldn't take it too seriously, he's probably accepting. If it really bothers you, you can always ask him (and try to make sure that you're not going through a phase)