As Ted begins his new career as a professor and is about to meet his future wife, Lily forces Barney and Robin to have "the talk" and define their new relationship.



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Episode cast overview:
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Lily is sadder to learn that Barney and Robin aren't a couple more so than Barney or Robin. But after that, Lily catches Barney and Robin making out, the two who confess that they have been in a sexual relationship over the course of the summer, a fact they were hiding since they didn't want to make a big deal out of their undefined relationship. Lily thinks that Barney and Robin need to have "the talk" to define what they really mean to each other. They refuse since they are quite happy having sex and that's it. When Robin is forced to go on a date with Brad, Barney and Robin almost get to the point of feeling the need to have the talk. When they still can't go through with it, Lily, ultimately with some help from Marshall, comes up with a plan to force them to have the talk. Even if they do have the talk, will they come to any conclusions? Meanwhile Ted is preparing for his first day as a college professor teaching Architecture 101. He is trying to decide what kind of professor he ... Written by Huggo

Plot Summary | Plot Synopsis


Comedy | Romance





Release Date:

21 September 2009 (USA)  »

Company Credits

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Technical Specs


Sound Mix:


Aspect Ratio:

1.78 : 1
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Did You Know?


The scene in which Ted runs out of his lecture hall was filmed at UCLA. See more »


When Lily locks Barney and Robin in Robin's room so they can have "The Talk", she is meant to have unscrewed the doorknob. However, Lily is not holding the part that was unscrewed, Robin is. See more »


Ted Mosby: [about Barney and Robin] You do realize they were lying, right?
Lily Aldrin: No, Ted. They don't realize that they weren't lying.
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References Gremlins (1984) See more »


Oxford Comma
by Vampire Weekend
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User Reviews

A fine comeback with some funny jokes
2 May 2013 | by (Austria) – See all my reviews

In the overall 89th episode and the first one of the fifth season, we see some things changing in How I Met Your Mother. Narrator Ted finally decided to be a college professor and in his first lesson, he's already facing some major difficulties, . how many f's the word 'professor' has or if he should wear his newly gotten fedora. But bigger than that is the story part with Barney and Robin who've been sleeping with each other for quite a while and also have love-like feelings, yet are terribly afraid of any sort of commitment. To define their relationship, Lily forces them to have 'the talk'. I'd say this is a fine comeback for the highly successful sitcom and it provides what fans were looking forward to see. I thought there were many cheesy jokes and Neil Patrick Harris and Cobey Smulders didn't do well in their sort-of relationship. Still, it's better than most of the episodes in the disappointing season 4 because I really enjoyed how Ted was doing as a professor and there were some nice running gags in there. I thought it was great when future Ted just casually mentioned that the mother of his future children was sitting in his course and the scene at the end where Barney and Robin go to eat brunch and the rest of the group is looking at them was pretty awesome. All in all, "Definitions" is by far not a perfect episode, but surely an enjoyable and amusing one.LESS

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