The Wedding War by Liz Talley

Once upon a time, Melanie Layton and Tennyson O’Rourke were inseparable—but their friends-4ever promises were shattered when an explosive secret was revealed at Mel’s wedding, a secret that destroyed her family. The two haven’t spoken for the past twenty-some-odd years, and they’d be happy if they never crossed paths again.
But now Mel’s daughter and Teeny’s son have fallen in love—and announced their engagement.
Which means the two women must tolerate one another and play nice long enough to plan their children’s dream wedding. From the beginning, they clash. Melanie imagines a classy, elegant event, in keeping with tradition. Teeny’s vision is a bit more extravagant, and thanks to her habit of marrying well, she’s got the cash to plan the flashiest wedding of the season.
Complicating matters are the men in their lives: Tennyson is falling for the wrong guy, and Melanie is trying to hold on to a flailing marriage. Amid the flurry of cake tastings, dress fittings, seating charts, and bridal showers, Mel and Teeny confront their past mistakes—with twenty years of pent-up drama.
When the day of the wedding finally arrives, their friendship might just be something old and something new.