A glitch in the matrix

Explanation, geno, was a possessive and protective lover.

That didn't change when he became error, but he did forget about reaper for a good long while. While when he was geno, his possessive protective Nature was very mild, like mostly glaring at others who flirted with reaper if any even did.

But as error, that kinda just..grew...sure he did fall in love with nightmare and they got together, but what would happen if he suddenly remembered about his first and only lover besides nightmare? What then?

(Different things happening, personalities may be different, I got this idea while I was doing a gacha club version of possessive geno turned error over reaper and nightmare. Also nightmares the same way like error, and it well be those three together. Etc