Gray: There are some things I excel at: Exercising rigid control over every aspect of my life. Making sensible decisions at every turn. Being organized, predictable, and responsible.

In short, I'm boring as hell and in desperate need of a change. Luckily I have my best friend by my side and a newly written to-do list to guide my way through the murky waters of finding happiness. It's all very promising at first, but as weeks pass, I start to realize that the best part of my day has always been Kai. And when I see him out on a date with some guy? Let's just say I'm definitely not happy about it.

Kai: I'm back in Boston after ten years of traveling, and I've fulfilled all my goals: See the world. Figure out what to do with my life. Get over my impossible crush on Gray. Check, check, and check.

Life's good until I accidentally find Gray's happy list, which contains some very interesting things that friends never ever do with each other. And as weeks pass, it becomes clear those not-so-innocent parts are the ones Gray is determined to explore with me. I can't resist him, and pretty soon I'm forced to admit that I'm not as done with my crush as I thought I was . . .

Contains mature themes.