It's the thriller set in NYC called "Best Intentions" by Emily Listfield and published by Atria Books.
This is courtesy of the blog, "Write Meg!"
The novel is described as:
What happens when you think you know the person you love — and you’re dead wrong?
“From the acclaimed author of Waiting to Surface comes the story of four college friends whose reunion reawakens old desires and grudges — with fatal results.
After tossing and turning all night, thirty-nine-year-old Lisa Barkley wakes up well before her alarm sounds. With two daughters about to start another year at their elite Upper East Side private school and her own career hitting a wall, the effort of trying to stay afloat in that privileged world of six-story town houses and European jaunts has become increasingly difficult, especially as Manhattan descends into an economic freefall.
As Lisa looks over at her sleeping husband, Sam, she can’t help but feel that their fifteen-year marriage is in a funk that she isn’t able to place. She tries to shake it off and tells herself that the strain must be due to their mounting financial pressures. But later that morning, as her family eats breakfast in the next room, Lisa finds herself checking Sam’s voicemail and hears a whispered phone call from a woman he is to meet that night. Is he having an affair?
When Lisa shares her suspicions with her best friend, Deirdre, at their weekly breakfast, Deirdre claims it can’t be true. But how can Lisa fully trust her opinion when Deirdre is still single and mired in an obsessive affair with a glamorous photographer even as it hovers on the edge of danger?
When Deirdre’s former college flame, Jack, comes to town and the two couples meet to celebrate his fortieth birthday, the stage is set for an explosive series of discoveries with devastating consequences.
Filled with suspense and provocative questions about the relationships we value most, Best Intentions is a tightly woven drama of love, friendship and betrayal.”
For more information - check out "Write Meg!" by Friday, May 5!