He had plenty of time to build up anger and frustration. He had plenty of time to build up self-righteousness and walls so high she'd never be able to get around them. He felt entitled to them. She had forced him to be a better person. She wouldn't let him run from his misdeeds. She held him accountable. She offered to bolster him up in the face of them. And when he wanted to return the favor? She shut him down. After she told him not to run, that he needed to face his demons, she couldn't follow her own advice. Instead, she left him not only to face his demons, but hers as well. Bellamy felt entitled to the rage that had been simmering just underneath the surface all these weeks.
So when Clarke appeared, he could only offer up a huff of agitation when all that rage also abandoned him. That entitlement evaporated and the self-righteous anger was no longer at his fingertips. Because looking at her, he didn't see the girl who abandoned him, he saw the girl who would do anything to save her people - even lose herself in the process. He wouldn't look at her, keeping mindful of her in his peripheral vision. Instead, Bellamy studied the floor and then his hands, lacing them loosely together so he could intensely search the lines and callouses for all that proverbial blood he knew was there.
Clarke spoke and he hesitated, eyes fluttering shut for a brief moment. He set his jaw, the muscle in his cheek jumping, before finally lifting his dark gaze to find her. "Hey," the echo rumbled in his chest. "I'd say it's been awhile, but it's just me." The flippant comment made him feel less antsy and more himself. He studied her for a quiet moment, "You okay?" the question left his lips before he realized it and Bellamy regretted it. She didn't deserve his concern, but in spite of everything he wanted to feel, concern was all he could come up with for now.