Librarian Marcela Ortiz has been secretly in love with her best friend for years - but when he gets engaged, it's time to move on. Before she gets the chance, she has a bigger problem to contend with in the form of Theo Young, ex-NFL player and older brother of the man she loves.
When she discovers Theo's plans to confess his feelings for his brother's fiancée at their engagement party, Marcela stops him - despite how tempting it is to let him run away with the bride-to-be. Managing to convince Theo to sleep off his drunken almost-mistake at her place, when they arrive at a family brunch the next day, everyone wrongly assumes they hooked up.
Since Theo needs a cover for his feelings for the bride and Marcela needs a distraction from her unrequited feelings for the groom, they decide to roll with the lie. Until one late night at a bar, they take it a step further. Soon, they're exploring the simmering chemistry between them, whether in library aisles or Marcela's bed.