Iris Hagarty has just about had it with weddings. After witnessing one too many meltdowns over flower arrangements, she takes to the internet to vent about the trials and tribulations of being a bridesmaid to demanding and ungrateful brides. She finds she is not alone, and soon becomes the moderator of a Facebook group full of other bridesmaids, eager to share their own horror stories.

Enter Iris’s sister Jasmine, the golden child and their parents’ obvious favorite, newly engaged and wanting none other than Iris to be her maid of honor. Knowing full well that Jasmine doesn’t need a wedding to bring out her spoiled side, Iris buckles in for a bumpy ride. At least now she has an outlet—one full of new online friends hungry for juicy details.

But as the Bridesmaids Union grows, Iris finds it harder to keep under control. And she even has some doubts about whether there will be a wedding after all. While Jasmine’s fiancé, David, seems smitten with his bride-to-be, Iris is less sure about her social-climber sister’s intentions. Though that could just be because Iris is having trouble keeping her own eyes off of the groom.