What happens when your plus one becomes "the one"?

Holly Haggerty and Roth Esterly are two besties with everything in common--they're neighbors, career-driven, and commitment-phobes. Tired of always being set up on dates by well-meaning friends and family, they take matters into their own hands: they will be the other's plus one--a little friendly arrangement between friends.

Easy…until a steamy night where they cross the line. But that's okay, they'll add an addendum--one that includes a little action between the sheets…on top of the sheets…and without the sheets. But there are rules. Dating and sex are exclusive until one of them decides to terminate the agreement. No slumber parties. And if either party becomes emotionally involved they will break things off with no hard feelings.

When unexpected news changes their plans and turns their fun arrangement into something more serious, Holly and Roth must come to terms with what's more important--what they thought they wanted, or what they really need.