Digression over, I return you to the story. So yes, Shane stupidly admits he can't be compelled. The great thing about being uncompellable is pretending you're compelled and either lying or telling the truth -- whatever suits your purpose at the time. Shane's too crazy to remember that, though, so Rebekah orders Kol to beat their newest captive until he tells them where to find the cure.
When Rebekah returns to the library, she proposes a game of Truth or Dare. She really is a thousand-year-old teenager, isn't she? When Elena chooses dare Rebekah compels her to tell Stefan the truth about Damon. Closing her eyes, Elena says, "Being with Damon makes me happy." Rebekah scoffs at this and says, "Clowns make you happy, Elena." She does that, just to drill home my earlier contention that we're working in the horror genre, because what kind of freak is made happy by clowns? When Rebekah orders Elena to dig a little deeper, our girl must obey. Elena says, "When I'm with him, it feels unpredictable, like I'm free." When Rebekah asks how Elena feels when she's with Stefan, Caroline tells her to stop and Rebekah says, "She can't. She's compelled."
Answering the question about Stefan, Elena says, "Lately, I feel like I'm a project -- like I'm a problem that needs to be fixed. I think I make him sad, and I can't be with someone like that, because when he looks at me, all he sees is a broken toy." Rebekah beams at Stefan, then turns back to Elena and says, "Do you still love Stefan?" Elena says, "Yes." Rebekah: "Are you still in love with Stefan?" Elena: "No." There's some beautiful silent pain from both Paul Wesley and Nina Dobrev, here. It's not surprising, but it's wonderful to watch.
Rebekah rises, turns toward Stefan and says, "Did that hurt -- having someone you love drive a dagger through your heart?" Stefan tells Rebekah to go to hell, so she repeats the question. Compelled to answer, he simply says, "Yes." Squatting down to look him in the eye, Rebekah says, "Welcome to the last 900 years of my life."