"Slap Bet" is the ninth episode of the second season of the American sitcom How I Met Your Mother.
Ted, Marshall, Lily, and Barney find out that Robin never goes to malls and refuses to explain why.
Barney then starts working his way through hours of Canadian porn, which he finds both depressing and tedious.
After trying to avoid the issue, Robin tells Ted that she got married in a mall, after which her husband moved to Hong Kong without getting a divorce.
Ted promises to keep it a secret but tells the gang after Lily begs him, so Marshall slaps Barney.
To try and help Ted, law student Marshall searches a legal database and he reveals that there is no record of a marriage license for Robin in Canada.
The beginning of the video shows Robin, dressed as a schoolgirl, seductively pleading with a teacher not to give her detention.
Staci Krause of IGN gave the episode 8.9 out of 10, describing it as "hilarious" and "a good break from the progressive storyline the show usually boasts".
[5] In 2010, Joyce Eng of TV Guide called the episode "possibly the show's finest half-hour" and said, "nothing will ever be or beat 'Slap Bet'".
[11] In 2012, Eric Eisenberg of Cinema Blend chose "Slap Bet" as the best episode of How I Met Your Mother.
Eisenberg commented, "the highlight of "Slap Bet" is the use of misdirection", and described Robin's singing as "maddening and hilarious".