Ariana Grande got a surprise at her concert Wednesday when Justin Bieber showed up to help her sing a few songs, E! reported.

Bieber joined Grande at her show at The Forum in Inglewood, California, first helping her sing one song, then getting a chance to sing one of his own and finally rejoining Grande for one more song.

Bieber first joined Grande's performance of "Love Me Harder," singing The Weeknd's lines.

Bieber encouraged Grande to "go take a break." Before singing his "Where Are U Now," Bieber pumped up the crowd. Bieber performed "Where Are U Now" and performed some flashy dance moves with some backup dancers.

After he was done with his song, Grande returned to the stage.

The Canadian native asked the crowd if they wanted to hear one more song. The crowd roared in appreciation to this.

Bieber and Grande performed Bieber's 2012 hit "As Long As You Love Me" together. The song kept the two separate for most of the performance until the very end. Bieber calls Grande over and tells her to stand in front of him.

He then put his arms around her waist briefly. Grande appeared to not enjoy the gesture, but she laughed and casually disengaged from Bieber.

The two ended the song, and Bieber made sure to give Grande a hug before saying goodbye to the crowd.

The hug was harmless, but the waist grab appeared to have caught the attention of Grande's current boyfriend Big Sean.

The Twitterverse had a good laugh at the situation, posting images of a tweet that was tied to Sean, as well as a picture of him with an unhappy look on his face.

"This kid is about to learn not to touch my girl like that. Beliebe that," he supposedly tweeted.

TMZ reported that the Big Sean tweet did not happen. The rapper's team said it was fake and that he and Bieber are actually good friends. The website does not note whether the tweet was seen by some and later deleted, but there is a screen shot of a tweet that contains the supposed Big Sean message.

If Big Sean was upset, Bieber did not know it. After the concert, he displayed an upbeat attitude on his social media account.

"Love the stage," Bieber tweeted. "Thanks for having me @ArianaGrande and thanks LA. Gotta tour again soon :)"