Oh, this question takes me back to stumbling upon 'The House in the Cerulean Sea' by TJ Klune. It’s this warm, whimsical fantasy with a middle-aged caseworker, Linus, who’s reluctantly thrown into a magical orphanage—and Arthur, the enigmatic caretaker, totally fits the 'gay dad' vibe. Their slow-burn romance is layered with parenting struggles (six peculiar kids!), and Klune nails the balance between heart and humor.
What’s cool is how it subverts expectations—Arthur isn’t just a stereotype; he’s fiercely protective, vulnerable, and flawed. If you dig found family tropes, this one’s a gem. For something grittier, 'The Captive Prince' trilogy has Laurent, who evolves into a paternal figure politically, though it’s more court intrigue than domestic fluff.