Demi Lovato stopped by "Watch What Happens Live" on Thursday, and she was asked three very difficult questions.

Lovato joined Andy Cohen and Jessica Alba on the show, notes E! News.

She was told she had three questions, and she could only "plead the fifth" for one of the questions.

The first round was shag, marry and kill, and her choices were Joe Jonas, Justin Bieber and Simon Cowell.

"I'd kill Bieber," she said. "I'd kill simon. F*ck, I'd kill Joe, too!"

She had a little fun with the question, but she then said make a clarification.

"No, Joe and I are good friends, so I wouldn't kill him," she said. "I'd keep him around."

But Lovato made it clear that she would definitely not marry Jonas. The former couple first met in 2007 on the set of "Camp Rock."

Alba felt she needed a bit of clarification and asked the 21-year-old singer who she would shag.

"None," Lovato said.

The next question clearly made Lovato uncomfortable.

"Not including your own behavior, what is the most scandalous thing you ever saw a Disney Channel star do?" Cohen said. "And you don't have to name a name."

Lovato decided to skip that question, saying she couldn't answer it.

Cohen finally asked about her childhood friend Selena gomez.

"You recently unfollowed your BFF Selena Gomez on Twitter," he said. "So much speculation about this! Can you tell us why?"

"Um, I plead the sixth, if that's in the game," she said.

But, Cohen wouldn't let it go at just that.

"I think it's just one of those things where people change people grow apart," she said.

But she also had some great things to say about Britney Spears. The two worked together for "The X Factor."

"I didn't know what to expect when I was about to work with her," she said. "I just knew I was really excited. I just remember her having all these little moments where someone would come out on stage and she would just say it like it was. She didn't care! She would just say, like, 'I don't get it.' It was really funny and endearing the way she would say it." 

Lovato added that Spears was kinder with the way she spoke to people, which is something that doesn't come as easily for her. She said you can read her reactions clearly on her face.