"You make a horrible parent"

WARNING: READ THE FOOKAN TAGS

Summary: After Tomioka Giyuu left Tanjiro, he ran into Kibutsuji Muzan. They found each other, but before they managed to fight, they heard a wail, only to see a little demon girl no older than the age of five. The girl mistaken them for her parents, Giyuu was nervous while Muzan wanted her dead. Giyuu made a deal with Muzan that he will help him find the blue spider lily if he spares the girl's life while staying away from the Demon slayer corps, He agreed

Little does Muzan know, Giyuu is growing the flowers inside him due to his hanahaki disease that's been passed down from generations in their family until they find the person they love

Or: Giyuu and Muzan got forced to raise a kid together and get married while Giyuu keeps this from his fellow demon slayers. What could go wrong?
(In my defense woman you simp for Douma)
[Side note, this is for shits and giggles please dont take this too seriously XD]