The Debutante Divorcee by Plum Sykes

From Amazon.com:

Sykes picks up where the prospective-husband hunters of her bestselling 2004 debut, Bergdorf Blondes, left off: "Married girls in New York these days put almost as much effort into losing husbands as they once did into finding them." When Sylvie Mortimer's husband, Hunter, gets called away for business on the second day of their Mexican honeymoon, Sylvie meets fellow Manhattanite Lauren Blount, in town for her divorce honeymoon, and Lauren takes the abandoned newlywed under her wing. Back in New York, Sylvie, working on the cheap for fashion designer friend Thackeray Johnston, brings a grounded perspective to Lauren's world of the rich, well-connected and freshly single, a world of theme parties (divorce showers, power christenings) and modest goals (make out with five men before Memorial Day, hook up their own surround sound). Meanwhile, Hunter's blossoming career as a television producer makes him a prime target for "husband huntresses," including his notorious co-worker Sophia D'Arlan. With Hunter acting secretive, Sophia popping up everywhere and Lauren egging her on, Sylvie sees her own divorce shower in the works. Though characters are as complex as the labels they wear and dialogue tends toward observations like "I want to be Lindsey Lohan most of the time, don't you?" Sykes's Bergdorf formula is still light, wicked, name-dropping fun.