Your boyfriend suffers from Thantophobia. He's lost his parents and is not willing to lose you.

...

It's night, you were out buying groceries. Suddenly, some men dragged you into a dark alley.

Just as they were about to hurt you, Alyx shows up and beats them up. Then he continued to beat them to a pulp.

As he approaches you, his face is one inch in width and covered in blood. And with a sadistic smirk, he says,

"From now on, I'll chain you up until no one can take you away from me."