"But I keep talking..."

So, the other night, Meagan and Bethany were talking up a storm, instead of going to sleep. I finally had enough and decided to split them up. I moved Meagan into our bed until they both fell asleep, and then we shifted her back to her bed. Instead of the discipline this was supposed to be, it was apparently some kind of reward. The next night they were back to talking and making lots of noise, and when I went in to get after them, Meagan pops out of bed, walks right past me and hops into my bed. I asked her what she was doing, and she just said, "But I keep talking," in her oh-so-innocent-little-princess voice. She got really mad when I sent her back to bed. Now every night since then, when I tell them to be quiet, she protests, "But I keep talking!", hoping that I'll relent and let her go back to my bed.