The Guilt Trip by Sandie Jones

 I will start by saying that I didn't like the first 2/3 of this book, but the last 1/3 redeemed it.

The premise is that a bunch of friends/family members get together for a destination wedding in Portugal. And someone ends up dead.  Rachel is married to Jack. Her best female friend is Paige, wife of Noah, who was Rachel's best friend (the focus of unrequited love) for years. The happy couple is Jack's brother Will and his fiancee Ali, who used to work for Jack but left to work for his major competitor. So there's a lot of potential tension when this fun crowd stays together in a villa in Portugal. Rachel thinks Jack had/or is having an affair with Ali. Paige isn't sure she still loves Noah. Rachel is beginning to remember how much she loved Noah. The first 2/3 of the book consists mostly of various members of this group sniping at each other or, in Rachel's case, stressing out over every little thing, which I found kind of tedious. But then something happens at the reception that made the story a lot more interesting. 

In some ways it reminded me of The Guest List, which was set at a destination wedding on an island off the coast of Ireland--and was equally depressing.