I'm not against ringing the changes when a sitcom introduces a new premise. When Robin and Barney became a couple, for example, it's to be expected that the writers would try to wring every bit of humor from their situation, exploring all the ways the dynamic changes.
But I found tonight's exploring of the couple-coupling phenomenon — you know, the one where a couple dates another couple and tries to forge a long-term relationship — more than a little tired. It's not that "The Sexless Innkeeper" didn't zip pleasingly along. And Lord knows it ended with a nice zinger. But it's not like this same premise hasn't been done on, well, just about every sitcom that features a couple. As funny as HIMYM managed to make it, I sensed an unpleasant sense of self-satisfaction with the idea, as if the writers were congratulating themselves on their cleverness. I don't think that's warranted for this kind of by-the-numbers setup.
In fact, didn't we all know that this episode, or some variant thereof, was in the offing the moment we saw Lily's excitement about Barney and Robin's coupledom? Marshall and Lily have been trying to pair up with another couple for years, it turns out, always coming on way too strong ("If you leave now, Colonel Mustard just gets away with it!" Marshall protests as one candidate couple tries to make a quick getaway). So they turn into smothering, commitment-crazed internet dates when Barney and Robin come over for their first couples night. Their carefully laid plans to make good conversation and have a perfect apartment flow turn into Lily offering a margarita and Marshall blurting out "In Cabo I saw Sammy Hagar eating a Belgian waffle!" And in the most painful vignette of the evening, Lily berates Marshall through clenched teeth for putting the evening's game at risk: "What do you mean the egg timer is broken what are we going to use for charades sweetie?!" (It's funny because it's true.) In the last straw, Marshall puts together a song and photomontage of the evening at itwasthebestnightever.com (featuring Extreme's Nuno Bettencourt).
Naturally Robin and Barney try to avoid any such awkward engagements in the wake of "Worst night ever!", hurting Lily and Marshall's feelings. They ostentatiously move on to a Hawaiian couple who aren't yet sophisticated enough to be put off by their desperation, and Robin and Barney realize they want the couple-coupling back. Blah blah blah, you could see it coming. Sure, there's some good writing (Barney's excuse for why he and Robin can't go to the B&B in Vermont: "The U.S. Navy has found intelligent life at the bottom of the ocean, and for reasons I can't explain, Robin and I have been tapped to lead the mission"; Lily's angry epithet hurled at Marshall: "You're a sturdy cheese-bearing cracker!"). But this is a case where the too-familiar premise just drags the overall attempt down.