I suppose this lie goes either way - lying about something you have read and don't want to admit, or lying about something you haven't read because you want to impress someone (or some other reason). I don't really understand why you'd do either, really, although I guess I can imagine scenarios...
I suppose you might be embarrassed to admit you've read something (like Twilight or Fifty Shades) but if you enjoyed it, then good for you. If you're reading, I'm happy. Even if Twilight is...okay, I'm going to stop there, because the point of this is that I shouldn't be judging people for their reading choices, and that's something I have to work on. So yes, I suppose I can see a situation in which someone might want to hide the fact that they read (and enjoyed) something that's been put down by others (like me, yes, I am trying to learn to not be Miss Judgypants about Twilight lovers).
When I was an English Literature student, there certainly were pretentious people around who would judge you if you hadn't read their favourite classic. I can't remember ever lying about reading something I hadn't, but it's not outside the realm of possibility that I did while I was a student so I didn't look uncool to the hip Lit Student crowd (seriously). But these days I take it as a reading recommendation. If someone asks me if I've read something, and I haven't, they're probably asking because it's good and they think I should - so why lie about it? I can take their recommendation, read the book, and happily discuss it with them later. There's several books in my Off The Shelf 2013 list that I'm embarrassed to admit I haven't read yet, like To Kill a Mockingbird, but it seems pointless to lie about reading it.
So I can see how you might want to lie either way, and I can imagine scenarios in which I might have done so, but can't remember a specific instance where I lied about what I have (or haven't) read. And if you ever catch me mocking Twilight lovers, remind me that at least they're reading, and that's a Good Thing!
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