Hoshisenshi: I adore that music video! Can't tell how many times I've watched it. Could there ever be a more perfect theme song for this couple?
But I see your true colors shining true, True colors, that why I love you, so don't be afraid to let them show... Whoever made it is a genius.
And does anyone else ever wonder how Fujitaka would react if he found out about Touya and Yukito's relationship?
Really, I can't imagine anything else than that he would be very happy for their sake, not thinking it unnatural or anything like that. As you said, Fujitaka is very gentle and understanding, it would be quite out of character for him if he dissaproved with his son's partner of choice, more likely is that he would be happy as long as Touya is. As for Touya and Yukito keeping it kind of secret, I wouldn't reckon that's because they're afraid of Fujitaka's - or anyone else's, for that matter - reaction, it's just that Touya especially isn't very keen on letting people in on his private life. Take how he even won't admit to Yuki that he cares for his little sister - I would say he doesn't tell his father simply out of automatism, since he isn't used to talk to people about his life and feelings.