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Demi Lovato has apologised to fans after a tweet about pranking her bodyguard was criticised for trivialising sexual assault.

The singer said she hired a sex worker who walked into her bodyguard's room without permission and grabbed his "area".

Some fans were less than impressed with the prank, tweeting that this was sexual assault.

Demi has since deleted the tweet and apologised "if anyone was offended".

Image copyright Twitter/Demi Lovato

The now-deleted comment was in response to a fan's question about the funniest prank the singer has ever pulled.

"I hired a lady of the night in Vegas and sent her to Max's hotel room to surprise him," she tweeted.

"She walked into his room without permission and grabbed him in his "area" and he freaked the f*** out hahahahaha."

But not everyone shared Demi's amusement. Many called it sexual assault.

Others disagreed and defended the singer:

Demi Lovato has spoken openly about her experience with eating disorders, addiction and mental illness, including depression, suicidal thoughts and bipolar disorder.

Earlier this year, she said she'd considered suicide at the age of seven.

After deleting the controversial tweet, Demi wrote: "I could tweet something about craving jelly beans and it would offend someone".

But this was followed by disapproving tweets that she'd compared sexual assault to jelly beans.

Demi responded to the criticism by asking people to listen to her song Warrior.

"Of all people I know about sexual abuse," she tweeted.

"You don't have to educate me."

Warrior hints at various aspects of Demi's past, including her childhood.

The song's bridge goes: "There's a part of me I can't get back/A little girl grew up too fast"

"All it took was once/I'll never be the same."

Demi then tweeted an apology to those she may have offended.

Demi's bodyguard Max has since responded online, agreeing that it was "a joke and a fun prank".

He also replied to Demi's apology and insisted that he wasn't offended.

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