Rurik felt the wall at his back and the force of Kai's weight against his front. The vampire had him by the arm, in a very delicate position. If he tried to break away, first off he wouldn't get very far, secondly, Kai's grip would likely break his arm. Healing, and especially self healing, was not one of Rurik's strengths.
"I didn't do this, Kai. Why would I? You were sleeping in my bed, or did that escape your notice?" antagonising Kai was not a wise choice, Rurik knew, but he hoped if he kept calm and indifferent to his attack, Kai would realise he was sincere.