It's no secret that Arya Stark (Maisie Williams) has started getting on some people's nerves . Her ruthless personality was crucial when she was out on her own, but it's causing a lot of problems now that she's back at Winterfell, especially between her and Sansa (Sophie Turner) . Arya seems to be purposefully driving a wedge into their relationship, and it's not quite clear why — or, is it? Reddit user ScienceMuddafucka took to the forum to detail his theory on why Arya's acting so strangely (key word: acting), and it has everything to do with taking down Littlefinger (Aidan Gillen).