What Is the Name of This Book? question

I read a book a couple of years ago. I can't remember the name of it but I can remember the plot, I either read the story on wattpad or in a book I found online. The plot is about a girl and her best friend who have recently finished college. The girl goes to her best friends house for Christmas but ends up bumping into her best friends brother and his friend. It turns out that the girl used to have a crush on the brother while in high school and they did date but he broke up with her and they hadn't spoken for a few years. Over the Christmas break the girl and the brother reconnect however this is ruined when it turns out the brother an his friend are engaged to 2 women but this turns out to be an undercover mission to get information on a crime or gang. In the end the girl and the brother end up together and the sister and brothers friend end up together as well.
I've been trying to remember the name of the book for ages and it's really bugging me that I can't remember. Does anyone recognise the story?