Demi Lovato's Threat to Kanye West: Treat Kim Kardashian Right or I'll "Come After Him" / "Heart Attack" Singer Happy With Proposal

Demi Lovato is done taking on X Factor judge Simon Cowell and is now moving on to threatening Kanye West. The "Heart Attack" singer is voicing her reaction to the Yeezus rapper's recent proposal to reality star mogul Kim Kardashian.

"I've known Kim for years and she's been such a good friend to me during some really hard times," the X Factor judge told E! News. "She deserves that Giants stadium! Thanks for telling me- now I can go congratulate her!"

But Lovato did say she wouldn't hesitate to defend her friend's honor if he ever decided to betray his new fiancé.

"I've told Kanye before that if he doesn't treat her well, I'm going to come after him!"

Don't worry Kanye, Lovato has no reason to "come after" you. After Kanye's proposal to Kim, Monday, it seems like the recently engaged Kardashian sister is quite content with how her baby daddy treats her.

"I'm the luckiest girl in the world," the 33-year old Kardashian sister told E! News. "I get to marry my best friend!"

How could she not be happy with Kanye's proposal? For the engagement party, Kanye flew Kardashian family and friends out to the San Francisco Giants stadium, commissioned a 50-piece orchestra to play Lana Del Rey's "Young and Beautiful" and Kanye's own collaboration with Keri Hilson and Ne-Yo "Knock You Down".

Stay tuned to see if Demi Lovato makes good on her threat. Something tells me Kanye is in it for the long haul.