Martha's eyes widen slightly as she realises just what Jack means. Any other day, she's sure that she wouldn't mind flirting with the possibility, but just as he'd said, he isn't exactly himself, and she'd really rather forgo the potentially bad route.
"Okay," she says as she watches him, finding that she's still reluctant even though she's quite aware that she really needs to leave.
"Okay." She says again it again, because she doesn't move after the first time, and even then, it takes her a moment before she actually pulls away from him. She starts to stand, saying, "Just... don't stay in here too long, all right?"