After fourteen years, the fire that brought the fun-loving and formerly adventurous Hank Murphy (Hus Miller) and Alexandra "Alex" Murphy (Marguerite Moreau) together has gone cold. Their home is for sale and the couple has fallen into an estranged and apathetic routine. They are getting divorced.
 
Desperate for inspiration, Hank takes off on a road trip to visit his eccentric father, Buck (Peter Fonda), in the wine country of Sonoma, California. Finally feeling a sense of freedom on the road, Hank meets Allison (Ingrid Vollset), whose wanderlust represents what Hank thinks has been missing from his life.
 
At home, Alex gets a phone call that makes her realize what she’s been missing. She leaves the kids with family, and sets off on a road trip of her own. In the middle of their separate journeys, fate brings the couple together at a roadside bar. They share a beer, have a good conversation and realize there is still a lot to learn about one another. Inspired, and with nothing left to lose, they challenge each other to a game that has only one rule: no matter what they ask each other to do, they can’t say no.
 
Drugs, sexual fantasies, entering a mud-pit pillow fight contest and much more make the game invigorating, uncomfortable and funny. More importantly, the game unites them and reignites the fire they once had.
 
Just when their relationship seems more alive than ever, one challenge that involves Miles (Hamish Linklater), the wacky owner of a winery, takes the game too far. Alex is mortified, and to make matters worse, Hank’s commitment to their marriage is questioned when Allison shows up in town. Alex decides the game, just like her marriage to Hank, is over.
 
Surprisingly, it’s Hank's wine-drinking, weed-smoking dad who helps Hank realize what he should have been fighting for all along. Hank gets Alex to accept one final challenge, so he can prove to her that their love is the one true thing they can’t say no to.