Now I dont know what a healthy father/son relationship looks like because I never had one but it seems to me that knowing “Dad likes blondes with big tits” might be slightly less scarring than being left entirely to your own devices with no oversight and going down a rabbit hole of xvideos fetish porn.
Theres 2 kinds of men in the world. Those that have beaten their dick, and fucking liars. Maybe this shit is weird and creepy, and maybe they have had honest and open discussions about sex and he is trying to give his son healthy attitudes towards it.