15 Saddest How I Met Your Mother Episodes
10. The Goat (Season 3, Episode 17)
Season three of How I Met Your Mother saw one of the worst fall-outs to ever grace the show. A couple episodes earlier, Barney and Robin had slept together, sending Barney into a paranoid state of guilt and shame. Believing he had broken the sacred Bro Code, he attempted to find a loophole in the rules, but couldn't do it even with Marshall's reluctant help.
Meant to take Ted to the roof of his apartment for his "surprise" birthday party, Barney decides to take him to Vegas for a crazy adventure, in order to atone for his mishap and admit his guilt.
Funny thing, though: Ted already knew about Barney and Robin's get-together. Robin had let it slip earlier, and though Ted seems to have forgiven Robin, he lets out his rage on Barney for his betrayal. After a fight, Ted admits that he thinks his and Barney's friendship has run its course, as Barney clearly doesn't care whether he hurts him.
The fall-out didn't last long, but seeing it happen was still a rough ride.