Awww. The psychopath got jealous Nagare was hanging out with someone other than him.
All this could have easily been avoided if Okaya just admitted his feelings for him...
This chapter makes it pretty clear the husband would have gladly joined Maria in avenging their son, if only she would have trusted him with the truth.
It's good there rekindling there love for each other. I just hope they both somehow make it out of this alive.