Demi Lovato was all smiles when she stepped out in New York City on Friday afternoon, but don't let her sweet expression fool you -- after her interview with Andy Cohen on Watch What Happens Live yesterday, she's definitely been letting her sassy side out lately!

During their chat, Andy asked, "You recently unfollowed your BFF Selena Gomez on Twitter. So much speculation about this. Can you tell us why?" Demi was hesitant to answer the question, but since she had already passed on a previous one, she had to share something. "I think its just one of those things where people changed and people grow apart," she said cautiously. Ok, so that wasn't that scandalous, but seeing as Demi reportedly detests Selena's on-again/off-again beau Justin Bieber, it was no surprise when she said she'd kill him in a game of f*ck/marry/kill!

Andy gave the 21-year-old singer Joe Jonas, Justin Bieber and Simon Cowell as her options, and she quickly said with a laugh, "I'd kill Bieber," adding that she'd also kill Simon and Joe. She tried to smooth things over by stating that shes good friends with Joe, but she still wouldnt marry or shag him. Ugh, that's not how you play the game! In case you missed it, watch her super lame interview below: