The best part of “License to Wed” comes fairly late in the movie, after you haven’t laughed nearly enough, after you’ve looked at your watch a half-dozen times, and long after you’ve decided you don’t care about the characters, not one bit. 

It’s when John Krasinski punches Robin Williams in the face.  “Yippee-ki-yay!” is what you’ll want to shout, all the while wishing you’d purchased a ticket to see “Live Free or Die Hard” instead. 

Williams plays Rev. Frank, a Robin Williams-like minister who teaches the 10 commandments to grade-schoolers using “hip” lingo like “Be Chill, Don’t Kill,” “Dad & Mom are the bomb” and “Cussin’ the man is outta hand.”  He also teaches a mandatory boot camp-style marriage prep course to adults who want to get married in his church. 

Enter optimistic, organized Sadie (Mandy Moore) and affable, go-with-the-flow Ben (Krasinski).  They’re young, in love and agree to take the class, which Sadie takes very seriously and Ben sees as a little ridiculous but figures, hey, how bad can it be? 

Let us count the ways this film attempts humor and ends up stepping into creepy:

1. Rev. Frank sends his evil-eyed, prepubescent henchman (Josh Flitter) to break into the couple’s apartment and plant a bug in their bedroom so that the Rev. and his protégé can listen from inside a van and make sure they don’t break Rule No. 2: No sex before the wedding.

2. The couple is given a set of fake twins to gauge their fitness for parenthood.  The mechanical “babies” look like 20-pound 60-year-old men who just got back from the racetrack.  Henchboy follows the couple around and uses a remote control to make the babies cry, spit up, poop blue goo and pee in Ben’s face when he attempts to change a diaper.

3. In a test of the couple’s communication skills, Rev. Frank has Sadie drive a car while blindfolded, with Ben in the back seat giving her directions.

Why Ken Kwapis, who’s directed some excellent TV shows (“The Larry Sanders Show,” “Malcolm in the Middle” and, most recently, “The Office”) chose to follow up the enjoyable “Sisterhood of the Traveling Pants” with this cloying comedy is a mystery.  He did get to cast the likable Krasinski, who more or less plays a version of his “Office” character, Jim Halpert, in this film.  And several of Krasinski’s “Office” mates make brief appearances here, which is distracting, but those scenes — especially the ones with Brian Baumgartner (picture Kevin from “The Office” in a hula skirt) — are the funniest in the film. 

Rated PG-13 for sexual humor and language. H1/2