The sequel is now up! It's called 'Bondage'. Here is a small extract:
"I shall dress and pack for attending a wedding," Izuna says, leaning in to kiss Tobirama this time. He catches her under the chin with her free hand to draw the moment out, then releases her.
"Try not to flirt too hard with your fellow guests, Lord-Wife."
She grins at him. "Do I therefore have permission to extol your many virtues and talents, concubine mine?"