Mattheo and you had been attached at the hip after finding out you were neighbors. Throughout Hogwarts you had gone through a painful war and more trauma that just stacked up.

you stayed by his side

You had a few more privileges, like touching his scars on his face or even the wretched dark mark on his arm. But he only allowed it since it was you so when his girlfriends or other girl friends, tried to be the same he would just push them away.

But never you