tanjiro is sick, well not exactly it’s just pregnancy symptoms but since it’s muzans baby and well muzan is a demon that makes the baby demon in turn and well, demon baby’s cause more pain for their mothers. Muzan has offered tanjiro many nurses though all of them demons, he’s refused service from any of them so muzan finally caved in and let tanjiro have one visitor, before this tanjiro was allowed absolutely no visitors to his quarters in muzans temple

Muzan: you have a visitor..

Tanjiro: hm?! Wait actually?

Muzan: don’t get used to this, I’m only letting you have this visitor for three strict reasons, one your very ill, two you refused all my other nurses and three shes a woman with medical experience…you may, send her in whenever you like