Lydia thinks she might be pregnant and begs Nate to keep it a secret until she gets confirmation; Jimmy realizes Nate is keeping something from him and becomes determined to learn the truth; Nate's life inspires Emma to write a country song.
Budding Portland restaurateur Nate's world is turned upside down when he comes back from a business trip to find his lothario best friend and roommate, Jimmy, is now dating his recently separated mother, Lydia. To make matters worse, Nate's previously disinterested dad, Harrison is now determined to win Lydia back and isn't afraid to use Nate to get what he wants. Stuck between his family feud and his best friend's first serious relationship, Nate's "new normal" forever changes his relationships with his parents, and severely handicaps his own dating life.
Significant Mother - Who's Your Daddy? Synopsis and Schedule