People We Meet on Vacation by Emily Henry

 Poppy marches to the beat of her own drummer. Alex is a buttoned-down play-by-the-rules kind of guy who had to take over running the family when his mother died and his father fell apart. The two have nothing in common. And yet, after meeting in college, they each become the other's missing half. And every year, no matter what else is going on in their lives, they take a platonic vacation together. Where could this possibly lead?

The story starts in the present, when Poppy and Alex are estranged after an ill-fated trip to Croatia (which we don't find out the details of till late in the book). Then she concocts a plan for them to try one more vacation in hopes of getting the relationship back on track. Unfortunately it's to Palm Springs in the desert in the heat of summer, and pretty much everything that could go wrong does. Can this friendship survive?

I had never read anything by Emily Henry but I will seek out some of her other work because I thoroughly enjoyed Poppy and Alex's adventures.