Lily: You've been together all summer. I don't get it.
Robin: Okay, It's like this. After we kissed, we sat down to have the talk.
[flashback to Barney and Robin in the apartment:]
Robin: We should figure out what this is.
Barney: Yes, we should. Or. Or... [they kiss]
[later, in bed:]
Robin: Okay, now, we have to figure this out.
Barney: Yes, we do. Or. Or... [they start kissing again and roll out of bed]