Mariah Carey made meme history in the early 2000s when a reporter asked her about Jennifer Lopez and she famously replied, "I don't know her." Since then, the line has become one of the "All I Want For Christmas Is You" singer's calling cards, and she pulled it out again while sitting down with Andy Cohen on Watch What Happens Live! on Sunday night. In addition to telling the host that she's not used to dating because she's "really quite virginal" during its "Plead the Fifth" segment, she also had to answer a question about Demi Lovato. Andy referenced the comments Demi made about the rumoured feud between Mariah and Ariana Grande, when she called Mariah "mean for no reason" and "unnecessarily rude" on Instagram. Mariah's response? "I don't know her, either."