Who's Your Daddy?

When Lydia suspects that she could be pregnant, she begs Nate to keep it a secret from Jimmy until she can find out for sure. As Nate makes every attempt to avoid Jimmy at all costs, Jimmy begins to suspect that his best friend is hiding something and makes it his mission to find out what. Meanwhile, Harrison makes his intentions to win Lydia back clear to Jimmy, setting off some not-so-friendly competition. Elsewhere, Nate's complicated life gives Emma everything she needs to write the perfect country song.