Demi Lovato's not only back, she's ready to knock someone – or at least one of their teeth -- out.
On Tuesday morning, she was sparring with FOX Sports personality and MMA trainer Jay Glazer and delivered a killer punch. Glazer was wearing a mouth guard, but she still managed to knock out one of Glazer's front teeth.
The aftermath of the episode was posted on Instagram. Glazer holds up his tooth while smiling to reveal a new gap in his mouth and says, (quote) "Demi knocked my tooth out!"
Demi hits back, (quote) "I'm sorry." But Glazer isn't buying it, replying, (quote) "She's not sorry," kind of like Demo's hit song, "Sorry Not Sorry." (Page Six)