The Wolf Among Us - The Wolf Among Us - Episode 1: Faith
I think lying to beast about having seen Beauty or not telling him could end up being the bad choice. After all, Beast could be worried that her Lamia personality has resurfaced and he's worried she might start another killing spree.
I doubt she's the one cutting people's heads though, since she only kills men how are abusive towards their girlfriends or wives. But it's something to think about.