"They said that about everything our parents did, too." It's a little too calm, and a little too easy to say, almost blase, because her life is all it has always been, even if it suddenly seems unreal to him, and it's all the way out of her mouth before she has any clue if he is the right person with the wrong mind, or is the wrong person and who has an entirely different past, life, family, because of all of this.

"Over here." Jo shifted back, and pushed herself up on a counter. Even though she had to grit her teeth and clench her eyes closed just to get there. "I need you to make sure that I don't stop once I start." Beat. "Or that I just don't fall down and slam my head on something." If she decides to pass out or something.

Yes, because passing out, and not screaming, was totally the bigger problem, since she couldn't make him fix it.
Even if he could, he might not have anyway. At least she would tell herself that, and let herself believe it.