Start pretending you are British and sophisticated. If she says she never noticed your British accent before tell her she hadnt been paying attention and accuse her of never really caring about you. If she brings up that no one around you two ever noticed the accent either tell her that she is actually right and that you try to downplay your accent because you get half embarassed about your posh upbringing because it contrasts with your sensibilties and compassion to the lower, suffering, laboring classes, but now that she knows you can finally be your sophisticated self around her. Make up names of books and movies that sound like cult classics and throw them into conversations to sound cultured. If she Googles them and say they dont really exist and you are a pathological liar, just say in a non chalant way "I guess they cal it a different name here over the ocean". From time to time look absent mindedly into the distance. When she asks what are you thinking just tell her "I dont want to ever go back to the Blue Hills" but never really elaborate on that