Criticism of Ariana Grande and Big Sean's relationship has been swirling the past couple of days as some point out that it became serious too fast.

A source told Us Weekly that the couple has "gone from 0 to 60 fast," Hollywood Take reports.

Both celebrities were on the rebound -- Grande after breaking up with Jai Brooks, and Sean after breaking up with Naya Rivers -- from long-term relationships.

The couple had rumors flying on whether or not they were together, and only recently made any acknowledgment of the relationship through social media -- and after getting caught on camera holding hands backstage at the MTV Video Music Awards.

"Sean asked Ariana out in a romantic way and they went to the movies," the Us Weekly source said, Hollywood Take reports. "Now it's gotten serious very fast. They are much happier than in their previous relationships."

Grande is coming out of a relationship paired with the loss of her grandfather in April.

"When her grandfather was dying, everyone was there for her. People flew to Florida to be with her, but Jai didn't," a source said, according to Hollywood Take. "Ariana just felt he wasn't there like he should have been."

And as the negative criticism of the "rebound affair" are stealing headlines, Grande is also facing rumors that she is a diva to work with.

While on a photo shoot in Australia, Grande was allegedly banning certain questions from journalists as well as had some sort of tiff with a photographer.

The list of banned questions included her love life, comparisons to Mariah Carey, a collaboration with Justin Bieber, the recent death of her grandfather, and her time working with Jennette McCurdy on the Nickelodeon series "Sam & Cat," Hollywood Take reports.

In addition, an Australian photographer was told to delete pictures but refused to, and Grande reportedly stormed off.

Grande defended herself later, denying the whole incident.

"It was just a photographer or something who got mad at me because I left to change my outfit mid photo shoot because I didn't like my top," Grande said on an Australian talk show. "I was like, 'Oh, I'll be right back!' and then I came back and he had left. I was like, 'Oh, s--t!' And then he came out and said all these ridiculous untrue things about me. I was like, 'That's not real. That's nonsense.'"