The Unhoneymooners by Christina Lauren

If you're just in the mood for some cute chick lit during the gloomy days of winter, check out The Unhoneymooners. Ami has her wedding to Dane planned down to every last detail--much of it free things she won through entering contests. But when everyone at the wedding reception--except Ami's twin sister Olive and Dane's brother Ethan--get food poisoning from the buffet, Ami insists that Olive and Ethan take advantage of her free honeymoon trip to Maui. Which would be great if Olive and Ethan could stand being in the same room. But neither wants to pass up a free trip to Hawaii, so they grudgingly set off, squabbling all the way. Until they actually start talking to each other and realize maybe they don't hate each other as much as they thought they did. Of course, the path to love is never smooth. But in this case it is hilarious.