Nope, that's not the case at all. In fact, he was never actually looking for "his" father! But you already know that by now, don't you?
yea, he is such a sweet heart :D I hope after meeting her father he can explain why he left her at the swings.
I thought he was in love with the girl and was looking to make sure that they didn't have the same father . . .
I'm pretty sure it wasn't that at all, considering the fact they both knew their fathers, and that the girl's father left because of a debt or something. I mean, it's a possibility, but you never know for sure.
He's doing it to confirm that they aren't related by blood!