[His face falls a little, and he looks down at his hands, leans against the wall.]

His body will contain him. Eventually.

[And he'll have to kill him when that happens. He's found a way around the orders to be here, be with Steve, protect him and help him and keep him safe, but as soon as the serum takes effect... he won't know if he can hold himself back any more.

He shakes his head a little.]

I'm not... good. For him.

[But he can't stay away. Gravitational pull indeed. He looks back at her, studies her in the darkness.]

I won't stop you. [He's not mine to keep.] But if you hurt him, I will kill you. [And I will make it painful.]