Kross had said that he'll not take another mistress.
That was what he had planned. Never had he thought to take another mistress. Now he had marked Lyra.
Well Isolde didn't know he had marked Lyra. If she knew that would be another headache. Right now she was throwing a fit just because Lyra was going with them to the South.
Even if Kross wanted, he can't leave Lyra. Right now Isolde was just being unreasonable and childish.
His mind couldn't help but compare her with Lyra. Lyra was younger and even after finding out she was marked, she didn't make a scene.
"She will be going with us Isolde. Behave yourself." Kross was trying to hold back his anger. He didn't want to lash out at her, but she made things difficult.
Isolde stumbled back when Kross let go of her hands, "K..Kross!"
For Kross that seemed to be the end of that discussion.