He is really pointing a sword at a neighboring prince, first in line to the throne, over a concubine. A low born concubine who is overstepping her bounds in all the étiquette of being around royalty.
I know love makes you stupid, but this is a new high for me. He should be thankful that Rashy hasn't been killed for her disrespect already. The Empress could just flex her power and get her yeeted out of existence.