It made sense. I mean, what kind of person one has to be to let their family member go out with a random person? I know for a fact that he is the little girl's real grandfather; by real, I mean the love and concern for each other is real; I don't know if she's his biological granddaughter or not. Anyway, the love can be seen in their eyes. People can't fake that sort of feeling.
So, in conclusion, he has a skill that lets him know that I'm not a danger to his granddaughter by any means. Hmm, maybe it's some kind of skill where a person can detect malice? Wait a minute. What is this familiar feeling all of a sudden?
[You know if you're so concerned about that, maybe you should just ask him. Who knows… maybe that isn't much of a big secret, and he'll reveal it to you almost immediately.]