Muzan definitely turned Daki into a demon so he could have sex. When you're 3,000 years old, you definitely crave pussy. He would have turned Shinobu and Mitsuri into demons if he ever found out about them.
I'll treat you like a woman. You now have a clit. No more erections and you'll stay pussy-free. You'll can only cum through arousing and full balls while watching me cheating on you. It's what's the most healthy for our couple. [OC]