i’m so confused can someone explain it to me 😔

So I think it’s based on the awkward relationship between a father and their child. Since he believed his dad was an alien based on the fact they couldn’t get along any more. He was feeling awkward because he knows she’s not his daughter but is still trying hard to be that father figure. In the end, they have the same mindset and that’s what brought them closer together. Kind of like him reassuring her that they still have a positive relationship, and he wouldn’t change for the worse.