Theo couldn't stop himself from lying in Ernie's arms but he felt comfortable there despite the close contact with another person and the way he was still twitching. His bad hand was trembling like he'd just gotten through the Crucio, even his muscle memory having nightmares.
He was slipping into a dark and thoughtless sleep, growing heavier against Ernie's chest as the potion took hold, but he still managed to find some speech. "Don't stay. Leave when he gets here. Leave me and go." he wanted to make Ernie promise but he didn't have the time as the potion dragged him down and he slipped away into what was a mercifully peaceful sleep.