Save the Date by Mallory Kass
Summary (from the publisher): A romantic comedy of manners about a lavish wedding weekend gone very, very wrong with the slow-burn romance of Emily Henry and the fizzy humor of Sophie Kinsella. The Bride: Beautiful, seemingly carefree Marigold, is tired of being treated like a shallow it-girl. That’s one of the many reasons she’s excited to marry Jonathan—the handsome, kind, respectable doctor of her dreams. So, when a shocking secret from her past threatens to ruin her wedding, she’ll do anything to make it disappear...even if it means tracking down a man she vowed to avoid forever. The Maid of Honor: As the bride’s best friend, all Natalie wants is for this wedding to go off without a hitch. There’s only one problem: Natalie has secretly been in love with the groom since college. When Marigold disappears, Natalie is forced to ask whether she can keep burying her feelings for the sake of friendship...or if she’s ready to risk everything to pursue her own happy ending. The...