Amulet

Beast Boy buys Raven a necklace to apologize for something she overheard. However, it's not just an ordinary necklace, nope! It's guaranteed to make the person who wears it fall madly in love with the person who gifted it. Or at least...that's what the lady said when she sold it to him. But Raven knows better, and with revenge on the brain, decides it couldn't hurt to play along...