Muzan can shape shift into any form he wants, so if you manage to convince him have sex with you, he can take form of anyone you want.

That means, if his partner wants and he is ok with it too, he can turn himself into a femboy.

And sleeping with a Femboy is one of life’s greatest pleasures. But doing so with a femboy demon is a truly divine experience. The feeling of those soft, feminine curves against your body is simply transcendent. And when they nuzzle their head against you, purring with satisfaction, you realize you have just peaked as a human being.

In short, it is a fantastic experience. And if you don’t try it soon, you are truly missing out.