Headcanon #1

Reiner hardly knows how to control his emotions unless it involves sadness. Bertholdt is basically his pillar. Whenever Reiner lays wide awake at night (and this happens quite often) thinking about what could have been, what should have been done and what’s to come, Bertholdt will be secretly (or not so secretly because Reiner simply doesn’t notice) watching him beside him and swings a long arm across Reiner’s chest while feigning slumber. It’ll rouse Reiner from his dreadful thoughts and allow a small smile to show on his face placing his hand right over his, keeping it there while falling asleep.