That's more than understandable, the way their relationship had started was hardly smooth or ideal at all. At best Vegeta had wanted nothing to do with Trunks. At worst... he was a punching bag, physically and verbally. It had taken time, but it had also been Trunks who had even started Vegeta on his path of attempting to be a father for his younger version.

"Time changes things." Is how Vegeta sums it up, not really capable of going further into it. At least not easily. What he is able to get out at least; "Considering the circumstances, I am glad to had gotten this chance to see you again." After Trunks having left both times... not that this version of him knew about the second chance they had.