Fans were shocked when raw footage of Solange Knowles attacking Beyonce's husband Jay Z in an elevator went viral earlier this year; so it might not be shocking that the XO singer had a nice talk with her husband before they attended her sister's wedding.

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While the cause of the attack has yet to be revealed, rumor has it that it was because Jay Z was cheating Beyonce.

An insider told British magazine Closer that Beyonce wanted to make sure there was no drama between her husband and sister on Knowles' big day.

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"Jay Z was on his best behavior and stuck by Beyoncé's side, and their daughter Blue Ivy was there, too. Beyoncé had a big talk with Jay before the wedding and impressed on him how important it was that he do the right thing. He did, but it was a bit edgy between them and he wasn't relaxed."

They also said that Knowles gave Jay Z a little shoutout and pointed her finger at him while saying her speech when she talked on how important it was for her and her new husband, director Alan Ferguson, to trust one another.

"[Solange] talked about the deep trust between her and her new husband. It seems a little like she was scoring points at Jay's expense, and he looked very uncomfortable."

As for Beyonce, the source said that she was "on good form."

Even though she was not in the best of moods, she did try to her best to support Knowles.

"It wasn't easy bearing in mind how hard the past year has been for her. Jay did congratulate Solange and, although it was rather forced, it made Beyoncé happy."