BLACKPINK‘s Jennie and Billie Eilish are officially our new favorite duo! Jennie (BLACKPINK) | @jennierubyjane/Instagram Billie Eilish | @billieeilish/Instagram Jennie just interviewed the singer at the Hit Me Hard And Soft Spotify event in Seoul, Korea — but it felt more like besties hanging out! | @BLACKPINKGLOBAL/Twitter [Video could not be displayed] The two delved…