Casey has big plans for his first Valentine's Day with Mia. But Ben and Joel tell him that their rule is to never buy expensive Valentine's Day gifts for their ladies because doing so would set a costly precedent. Casey goes ahead with his plans anyway, and Ben realizes that he too wants to show Maddie how he feels. When Joel finds out, he decides to compete with them no matter the cost - and gets singer/pianist Michael Feinstein to perform.

Ben hopes to get his name inscribed on a shamrock at his favorite bar, but it looks like he will strike out in his efforts when he learns the establishment's owner is New York Yankee Nick Swisher (appearing as himself), with whom Ben has a bad history. Meanwhile, Mia and Maddie use a secret language to convey their apprehension about attending a charity event with Vicky.

Mia and Casey try to reschedule their wedding until after their baby is born; Ben learns that Joel is worried about crying during his wedding toast.