But it's not just about a boy and a girl, because it's Nancy: It's about doors. He's asking Nancy to voluntarily close a door, when she's never closed a door in her life. Nancy is defined by leaving doors open, because she always knows where the exits are. So when they've jumped enough levels to actually talk about what they're talking about, it still comes down to Andy asking her to do the one thing that she cannot ever, ever do. Willingly chuck a resource; give up some of that domain. That's how get caught, pinned down. Dead. And letting him think he has the "power," whatever the fuck that means, is charming and indulgent and also completely irrelevant to the question.
She lets him talk about the power until the bus comes, but she just can't resist. Daredevil Girl glints around her latte straw. "...That said, you never know what could happen in the future." She grins, nastily and lovingly, and he slaps the coffee out of her hands. "You have no idea how long I've wanted to do that," he says, eliciting cheers, and she blows the rest of it through the straw and into his face, and that's détente for now: We can pretend the bone exists or not, but I'm never dropping the one I've got.
Back in the motel Andy is extravagantly bitter, tossing himself around the room like a kindergartener in need of a nap. "Your mom won't release me," he not-really-explains to Shane, and then Nancy starts packing up. Why are they leaving? Well, according to Uncle Andy, it's because he was "starting to find his own thing," and she had to ruin it. And secondly, because Silas fucked up the plates. "We're on the run now, honey. It's what we do." It's what they've always done. Exits exist for eminent egress.
At the door are the Mommies, suddenly; Nancy answers with a confused smile and when they ask if she's "the grandma," Shane busts loose. "You cunts followed me?"
Nancy excuses herself and holds the door closed, staring Shane down. "We don't use that word." Grandma? "No, cunt. Or grandma. We don't use either. Can you deal with whatever this is?" That funny little Nancy move as she heads back to her frenzied packing, those hands like birds. Andy reminds her that he has the Power again and she nearly laughs out loud. "I know you do," she grins, like Kish just notified her he pees standing up.
Heading out again, to get more money and a new car from that mysterious place she always pulls these things when she has to. "Or to take a train to some quaint New England seaside village and leave you all for good. I haven't decided which." One of the Mommies, at the door, tries to be helpful -- "I drink too, sometimes" -- and Nancy just rolls her eyes, directing them to Randy and the Power.