- Josh Radnor (Ted Mosby)
- Neil Patrick Harris (Barney Stinson)
- Jason Segel (Marshall Eriksen)
- Alyson Hannigan (Lily Aldrin)
- Cobie Smulders (Robin Scherbatsky)
- Cristin Milioti (Tracy McConnell)
How I Met Your Mother — S6E11
Episode: The Mermaid Theory
Air Date: 2010-12-06
Runtime: 23 min
Overview
When Ted's new friendship with Zoey tests the theory that single men and married women can't be friends, he invites her husband, "The Captain," to hang out with them. Meanwhile, Marshall and Robin decide to spend alone time together, and Barney and Lily possibly have a fight.