Dear Sexy Ex-Boyfriend

Yes. It belongs to Lauren Blakely's "The Guys Who Got Away" series, though each book is written as a standalone romance with its own couple and can be read on its own.

The book is set in contemporary New York City, where both Summer and Oliver live and work.

No. Despite the title, Summer and Oliver have never actually dated — they've been close friends for years. The viral letter that kicks off the plot is about their friendship, and their fake engagement is what turns those feelings real.