How I Met Your Mother » The Mermaid Theory
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.
First Aired: 06 Dec 2010
This episode is seen by 317 users.