She and co-star Kendrick -- who was in all black -- both donned outfits that featured strapless, structured corset-style tops with plunging necklines.
Lively's appearance was one of her few public outings since her relationship with Justin Baldoni, her director and co-star on "It Ends with Us," soured and turned into multiple competing court battles.
As 2024 came to a close, Lively sued Baldoni, his production company Wayfarer Studios and some of the public relations strategists they worked with, alleging sexual harassment in a workplace setting, retaliation, breach of contract and intentional infliction of emotional distress.
While Lively claims Baldoni -- along with Wayfarer Studios CEO Jamey Heath -- engaged in inappropriate sexual conduct during the filming of "It Ends with Us" as well as retaliation against her, Baldoni has denied all of her allegations. On the same day as Lively's lawsuit, Baldoni and his production company accused Lively of launching her own "smear campaign" against him in their own legal complaint, which was aimed at The New York Times over their reporting on Lively's claims.
A few weeks alter, Baldoni and the other defendants filed a second lawsuit targeting Lively and her husband Ryan Reynolds.
Baldoni and his co-defendants claim Lively was the one engaging in inappropriately during production by, in part, "asserting control" over creative decisions. They also accused Lively and Reynolds of leveraging their "power and influence" in the industry to intimidate Baldoni and the film's producers.
With several lawsuits in the mix, the proceedings have been consolidated into one federal case in the Southern District of New York. The two are scheduled to head to trial in New York in March 2026.
The movie sees Stephanie (Kendrick) on her way to the wedding of Emily (Lively) - years after a joint murder-suicide mission landed one in jail, and one with a publishing contract.
Now, Emily is out of prison and set to wed a wealthy Italian businessman, played by Michele Morrone, and she wants Stephanie as her maid of honor. The trailer previews a reunion just as eerily charged and potentially violent as their first go-around, reviving the "what are her intentions?" question central to the success of the first movie.
The movie will be available to stream on May 1 on Amazon Prime Video.
Anna Kaufman contributed to this report.