Fans of Barney and Robin can be happy to know that the show pretty much jumped right into discussing their relationship. We learn that despite trying to hide things from the overjoyed Lily, Barney and Robin have been having a secret relationship all summer. However, the two of them have been trying to avoid defining their relationship, hence hiding it from Lily. However, when Lily finds out, she's determined to force the two to have the talk.
However, Barney is not willing to until Brad (the occasionally recurring friend of Marshall) asks Robin on a date and without the girlfriend title she has no excuse to turn him down. However, Barney shows up at their hockey date and ends up punching Brad! When the two return home, they end up being locked in a room by Lily and Marshall, until they define their relationship. They end up lying and calling each other boyfriend and girlfriend in order to get Lily to let them out. However, the two end the episode by heading to brunch (violating one of Barney's rules of keeping a girl from becoming your girlfirned), and holding hands. All together now.... awww.
Meanwhile, Ted was preparing for his first day of teaching Architecture 101. He was nervous and trying to decide how to teach the class and ended up in the wrong room teaching in front of an Econ class. He eventually made it to the right classroom ten minutes late and ended up just being a professor and not worrying about style as much as the material. Apparently the mother was in that classroom... so did they mean Econ or Architecture 101? Guess we'll have to wait and see. Bastards.