I’m not too sure Squall would have anything to say to him really – seeing as he always was a man of few words, if any (after all, Squall thought Laguna was a ‘moron’ after the first time he time-traveled into Laguna’s conciousness ;)).
Besides, it was never proven beyond doubt that Laguna really is Squall’s father anyway – the common idea (and what I believe) is that he indeed is, but that mostly stems from the dialogue Kiros says to Squall on the Ragnarok: that "you look a lot like your mother", but then he adds "but Ward says ‘thank God you don’t look anything like your father," which is meant to be a laugh at Laguna’s expense, and while not proving conclusively, it does indeed indirectly hint that Squall is Laguna’s son (to Raine).
I’m pretty sure the FFVIII Ultimania guide says more on the subject though.
Ellone: "You can’t change the past. I just found that out. When I was kidnapped, Uncle Laguna went on a journey to find me… But because he did, Uncle Laguna wasn’t able to be by Raine’s side when she died. Raine wanted to show Laguna her new born baby… Raine kept calling out for Laguna."
Since she wasn’t apparently pregnant by the time they got married in the ending cutscene, it’s most likely that the newborn baby is Laguna’s, and that because of a lack of mother and his search for Ellone, Squall was put in an orphanage.
just look at his story with laguna in ddff, so hilarious.