Discord has always admired Fluttershy in a way that would be viewed odd, and with his latest history of coldly betraying her, he had to step up his game. Even if he hadn't deceived her the way he did, Discord still would be forced to admit it some time--otherwise someone else might take her for themselves. He was famous for keeping what he desired to be within his claws and to be claimed rightfully his. One thing is getting in his way, though. Fluttershy simply has not treated him the same since the incident with Tirek. Little does he know, it is not her who has changed.