Bachelorette

On the night before an old friend's wedding, three frisky bridesmaids go searching for a little fun but find much more than they bargained for. With lovely Becky (Rebel Wilson) set to marry her handsome sweetheart, Dale (Hayes MacArthur), the remaining members of her high school clique reunite for one last bachelorette bacchanal in the Big Apple. Regan (Kirsten Dunst) is an overachieving, ueber-Maid of Honor who's secretly smarting over the fact that she's not the first to marry, while Gena (Lizzy Caplan) is a whip-smart sarcastic who's actually a closet romantic, and Katie (Isla Fisher) is a ditzy beauty who loves the good life. But when Becky insists on keeping the bachelorette party tame, the women proceed with an after-hours celebration of their own.

the official version from trailers.apple.com on July 21, 2012

Ten years out of high school, three unhappy single friends come together as bridesmaids at a classmate’s wedding, get drunk, get high, and trashwedding dress while romancing new and old loves and settling old business.