'The Rough Patch' - Season 5, Episode 7
Lily plots to break up Barney and Robin after they hit a rough patch in their relationship.
Air Date: November 9th 2009.
Lily: So when they blew up the Death Star, knowing full well there were hundreds of storm troopers on it, those were people?
Marshall: Well, it's called the Death Star, baby. They knew what they were getting into.
Barney: Can you imagine us getting married?
Robin: Well, we are committed to each other.
Barney: Most of your stuff's already in my apartment.
Robin: Might make taxes easier.
Barney: Speed up your citizenship.
Robin: Scherbatsky's so hard to spell.
Lily: Ted, it's just a rough patch. It takes time getting used to being with someone else. And they're both ... what's the nice word for selfish?
Marshall: If they're not happy, why don't they just break up?
Ted: Because they're too stubborn. Neither one wants to be the first to admit they want out. They're playing relationship chicken.
Lily: They're a perfect match.
Ted: Maybe that's the problem. You can't have two alpha dogs in one relationship.
Marshall: We have two alpha dogs in our relationship.
Lily: Sure we do, sweetie.