Why am I so afraid of Ndad knowing this?

Close to ten years ago I was in a desperate situation with a girl I was in love with. I didn't have anyone else to talk to, and went to my dad about it.

He actually did try to give me good advice at the time. Then he kept persisting. He would not stop asking me about her, if anything had happened with me and her, and what did or didn't happen.

He knew this bothered me and still kept on. He kept on for years, and still does. He's worked with people associated with her, talked to them about her, and then told me. Trying to get a rise. Would always drop indirect hints, and never stopped.

He went from bringing her up and hinting around on a almost constant basis, to every few weeks, to few months, and now about once a year he'll get really bad about it. Keep in mind, it took almost ten years for him to get to this point of only bringing her up usually once a year. And I'm in my twenties, and he's talking about a girl I loved years ago.

Over the course of this, there have been times where he asked if anything happened, I'd keep a level head, and tell him no. Then he would talk about how much of a whore he thought she was, trying to get a rise out of me. She wasn't, she really is a good person. But he doesn't know anything about her.

Recently hit the one year mark, and he started hinting around about her again. He's being persistent. Almost every time I'm around him, he's saying something to try and get me talking.

I've been getting more of a handle on everything, and have always been good at hiding my emotions when my parents try and push my buttons. I keep acting like it's no big deal that he's saying anything about her, and he's continuing, thinking it'll get me to go on about her.

Used to I would get really tense, nervous, and feel a lot of dread when he would bring her up. Now I still feel a little bit of that, but not as badly.

And I'm wondering if anyone, from experience knows the reason why I'm feeling this way. Why I'm still afraid of him knowing that I cared this person.