He can't walk away. Not again. He went to go get the serum for her from the Guest House, and when he finally caught back up with Fitz she was coding. She was dying right in front of him. Again. The image of her bloody and broken, lying on that cold hard floor with Coulson holding her; he hasn't been able to push that image from his mind since.
He took his eyes off her twice. Only twice, and both times she made it out barely alive.
He can't sleep. Not now, not until he knows she's okay. Then he'll never leave her alone like that again.
He can't- he can't leave her, so he sets up post right outside her glass room after Coulson leaves to go to bed. And just stands there, watching her monitors, making sure she's still alive. And that's exactly where Simmons finds him hours later.
He hears the scientists making themselves breakfast around seven. He has been outside Skye's room since nine the night before.
He hears Simmons' footsteps before she even rounds the corner.
Fitz went to go get the lab ready in case they get a mission, whilst she heads to check on Skye's vitals. When she rounds the corner of the hallway that leads to Skye's glass room, she sees him. Just watching Skye through the glass. Her and Fitz had just assumed everyone else was in bed, thus she was startled having seen him there. She walks carefully over to him, taking his appearance in.
"Why does it look like you haven't moved since I left you here last night?" She asks with a hand on his forearm.
"Because I haven't Simmons."
"You mean, you haven't slept at all?"
"That is exactly what I'm saying, what's it to you?" He snaps, annoyed at the line of questioning. He won't leave Skye, and he doesn't care what she has to say.
He turns his head in her direction and his eyes flash. She holds her ground.
"You need to go take a power nap right now. What if we get a mission, Ward? What will you do then?"
"I CAN'T LEAVE HER! " He punches the wall behind him then turns around and slides down the wall.
His voice is broken as he speaks to her once again, "I can't leave her again, Simmons. The last two times I left her she died, physically died. And I've been trying to keep up this façade but I just can't do it anymore. I'm so tired but sleeping isn't going to be worth losing her again."
Simmons slides down to sit next to him on the floor and squeezes his shoulder.
May's voice comes over the com, "We got a mission, briefing in five."