Ariana Grande gave her fans a truly wonderful treat last weekend. As she continued with her Honeymoon tour, Justin Bieber made a surprise appearance in Miami and performed with Grande in 'Love me Harder' which Bieber surprisingly forgot the lyrics to in one part of the song.

It was rare for the hit artist to forget the lyrics to the song he performs as he is one artist that gets his concert tickets sold out upon the announcement of his shows. But of course, Bieber is also human and makes mistakes, which he apologized to the crowd on the stage exactly after performing the duet with Grande.

While Grande was performing the song solo on stage in Miami last weekend, Bieber showed up surprising the audience singing what is originally The Weeknd's part in the song. At first he did splendidly then after a while, Bieber just danced through the song as he apparently forgot some of the lyrics.

It was unnoticeable at first, then the audience just found out that he forgot when he announced it himself on stage. "So I feel bad, I forgot the words Ariana," he told Grande while performing inside the American Airlines arena, "I've been trying to memorize them backstage for like an hour!"

Of course, Grande said, "It's okay," and the crowd just kept screaming for Bieber, obviously forgiving him and not minding about the minor mistake. Bieber also then posted his apology online via his Instagram account captioning a photo he posted with Grande, "Had fun with u Ariana, even tho I forgot all the words haha," he wrote.

Meanwhile, Bieber also posted his apology and gratitude on his Twitter account writing, "Thank you @ArianaGrande and thank you Miami," he wrote. While Grande wrote back on her Twitter saying, "I missed the stage. See u soon ;)" she added, "Thank u Miami babes and thank u @JustinBieber!!!"