Let it Roll by Sophie Kent

Left at the altar? Pick yourself up, dust your sexy off, and fall in love with your hunky best friend.
When Susan is dumped at the altar–via cocktail napkin–it is up to her best friend Kevin to help her recover. After a brief post-wedding-that-wasn’t coma, Susan finds herself in paradise, on her honeymoon, but with Kevin, not her groom. After some crying, paragliding, frozen margaritas and bad advice from her other best friend Liz, Susan decides to seduce Kevin and get rid of her pain with a rebound fling.
Kevin has secretly loved Susan for years and finally giving into her cuts him deeper than he could have expected.
He leaves her and severs all contact with her until six months later, when they are both vying for the same account–designing Chicago’s new opera house.
Competition takes on a whole new meaning for Susan when Kevin shows up on the arm of her arch nemesis, the cougar Francesca Costa. She now must not only vie for the opera house…but for her best friend’s heart as well.