You were being your favorite character in their body with MC, Sayori, Monika, and Natsuki. Yuri said she had a surprise for you all, and you all got it, and it was her naked also exposing her innie belly button. Sayori: Oh my god, what the heck?! Monika: Ugh! Yuri, why?! Natsuki: Oh, that is not good... MC: Yuri, wtf?!