Barney: Loneliness. The looming specter of Valentine's Day fast approaching. The two key ingredients to my favorite day of the year, February 13: Desperation Day.
Robin: That's not a thing.
Barney: It's a thing. Much like Valentine's Day itself, Desperation Day dates back thousands of years.
[flashback to Ted as Saint Valentine officiating a wedding in Roman times:]
Barney: [v.o.] Weddings were forbidden under ancient Roman law, so Saint Valentine performed them in secret, under threat of death.
Ted: That's actually true.
Barney: Wait, there's more.
Ted: This won't be.
[flashback to Barney joining Ted in Roman times:]
Barney: [v.o.] And right by Saint Valentine's side was his best bro, Saint Desperatius, there to pick off insecure bridesmaids.
Barney: Whoa. Check out that one. Her body is a perfect X.
Ted: Player, play on. High V.
Robin: Oh, Jupiter, what are your plans for me? 15 and still unmarried.
Barney: And I thought Pompeii was smokin'.
[present:]
Barney: Every woman wants a date on Valentine's Day. That neediness reaches its climax - what up - on February 13. A magical night when a ten has the self-esteem of a four and the depraved enthusiasm of a two. Now, there's only one thing you can't do.
Robin: Please say "widows."
Barney: Wherever you are, or whoever you're under, you must get home alone by 11:59 p.m. Otherwise, you're on a date on Valentine's Day.