Marshall and Lily are excited that Robin and Barney are dating as they now have friends who are a couple with who they can double date. Marshall and Lily don't have such friends because, unknown to them, they, to use Ted's vernacular, suck at being couples friends since they are so intense about making it a good time. Barney and Robin have no idea into what they are entering when they accept Marshall and Lily's invitation to spend a couples night at their place. After what they consider the worst night of their lives on that couples night, Robin and Barney don't have the heart to tell Marshall and Lily. After Robin and Barney eventually dump Marshall and Lily as their double dating friends, they are the ones who end up feeling shunned by the consequences. Meanwhile, Ted is sporting a new look - tweed - to make him look more professorial. He believes it is making him more attractive to the ladies. But when his latest "conquest" leaves the next morning, Barney believes that that look has now put Ted in the role of the sexless innkeeper. Ted tries to prove him wrong.
When Lily and Marshall realize that Robin and Barney are the perfect double-date friends, they try too hard to impress and come on too strong. Meanwhile, Ted gets a new nickname from Barney after an unsuccessful hook-up.
- Ted was rockin' a new professorial look, complete with the requisite tweed jacket. Despite Barney's mocking, Ted said chicks dig the professor look. Robin then recalled thinking her 10th grade math teacher was pretty hot -- and then openly wondered whether Harold was still in jail ("for tax evasion ... among other things").
Lily and Marshall invited Robin and Barney over for a "couples night," something they really enjoyed doing but something at which they sucked. We saw a string of failed couples nights at their place before Barney and Robin agreed to come over. They went, and while Marshall and Lily thought it was the "best night ever," Robin and Barney thought it sucked. Meanwhile, Ted was at a bar working his "chicks dig professors" theory, and it was going well with a woman who seemed to be into him.
Robin and Barney came back to the apartment and told Ted their night with Marshall and Lily "was like dating a chubby girl our mom made us call." Marshall and Lily were so nervous about their couples night that it made the whole experience awkward. They stumbled over their stories and freaked out about every little thing that went wrong -- including the egg timer breaking while they played Charades. Marshall even made a Web site about it: itwasthebestnightever.com (of course, it's real. Check it out for Marshall's duet with Extreme guitarist Nuno Bettencourt).
Ted's night hadn't really gone as well as it seemed, either. The girl he was talking to at the bar just ended up falling asleep on his couch before leaving in the morning. Robin and Barney realized the girl was never going to call Ted back and decided he was "the sexless innkeeper." Barney told Ted not to worry about it because many people have encountered the sexless innkeeper -- he even wrote a poem about his experience a year earlier. Barney said the girl took advantage of knowing Ted lived upstairs from the bar and figured he wasn't interested "nor probably even capable of having sex" because of Ted's tweed jacket.
Marshall and Lily planned a couples weekend in Vermont with Barney and Robin. Finally, Barney broke the news to Marshall and Lily -- that the Navy had found intelligent life at the bottom of the ocean and selected Barney and Robin to lead the expedition. Lily knew that was one of the excuses Barney gave to girls he was dumping, and she took the hint. That night, Lily and Marshall wondered where they'd gone wrong and Marshall let slip that he made a photo montage for Barney and Robin. Marshall had sort of become known for making such photo montages about mundane events, including getting Chinese take-out, cat-sitting for Lily's mom, and the cat funeral that followed. Lily blamed Marshall for the montage, but they proceeded to blame each other for having messed things up with Robin and Barney.
Back at the bar, Barney continued to mock Ted about being an innkeeper while he tried to tell Robin and Barney to clear things up with Marshall and Lily. They went over to apologize, but Lily and Marshall had another couple over and Lily shut the door in Robin's face.
Marshall and Lily saw Robin and Barney at the bar, but they didn't want to hang out because they were hanging with their new couple friends, Py and Shea, who'd just moved from Hawaii. Barney and Robin were immediately jealous and as they wallowed in their sorrow, they walked the streets as a couple and saw nothing but foursomes around them in a montage to the tune of "All By Ourselves."
Ted finally explained to Robin and Barney that they're a couple and that "couples need other couples," which was why they missed Marshall and Lily.
Robin and Barney set up a classic Hollywood romance ending to get their favorite couple back, starting by arranging a series of egg timers to lure Marshall and Lily out of their apartment and out into the New York City rain. Robin and Barney vowed to never hurt Marshall and Lily again and, after a bit of hesitation, Marshall said, "I think we can change them," and they all hugged it out.
Ted composed his own poem that he read to Barney about a "busty young lassie" who was "turned on by tweed." "With haste we did scamper to my chamber anon; we fell to the couch, and, bro, it was on.
"I unlaced her bodice; our passions grew deeper," Ted continued, "and, thus, ends the tale of the sexless innkeeper."
Barney thought Ted made it up, but the blond came out of Ted's bedroom and asked if he was coming back to bed. Ted ran off, telling Barney, "God, I love being single."
Robin came out of her bedroom and asked Barney if he was ready to leave for brunch with Marshall and Lily. Barney panicked, asking himself, "What have I done?!"