How I Met Your Mother
Episode Name: The Mermaid Theory
Episode 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.
Episode Number: 11
Episode Season: 6
Episode First Aired: 2010-12-06