He can respect Kal's feelings about fishing and eating creatures that were once alive, but Atlanteans have a much more 'circle of life' sort of viewpoint. Not all of them can communicate with fish like Arthur but he can't let that make him go on a hunger strike. Still, he does set down the net and pole outside the front door until he's facing Kal with an empty hand.

As much as the thought of him near his family again sets that instinctive part of him on edge, he tamps it down to face this level-headedly. Or as level-headedly as possible. Ultimately, it's their choice if they do or do not want to see Kal and hear his apology. "Mera has already told you what will happen if you lay a finger on Kaldur'ahm? Friendly or no."