Will jerks his arm up to let her leave, worried that he'll do something he'll regret if he tries to make her stay.

He just wanted to talk this out. He'd intended to share his own secret, so they could work things out. They were supposed to get better when they rescued Jack.

He rests his hands against the wall as she goes, and wonders how he managed to mess it up so spectacularly. But he's not going to give up on her.