The most surprising thing about this by-the-numbers comedy, in fact, is that it comes to us from writer-director Nicholas Stoller. He updated Kermit & Co. so delightfully in “The Muppets,” tartly reconceived the revenge rom-com with “Forgetting Sarah Marshall,” and scored on the small screen with both “Platonic” and the updated “Goosebumps.”

In You’re Cordially Invited, Witherspoon plays Margot, the sister of a bride, while the Anchorman star plays Jim, the father of a different bride. Margot and Jim don’t know ea