Barney attempts to hide the fact that he and Robin used to date, but Quinn finds out when sleep-deprived Marshall and Lily accidentally blurt it out. Meanwhile, Ted forces Victoria to write a left-at-the-altar note to Klaus explaining why she ran out on their wedding.
Elenco: Cobie Smulders , Josh Radnor , Neil Patrick Harris , Alyson Hannigan , Jason Segel , Bob Saget , Britney Spears , Candice Accola , Cristin Milioti , David Henrie , Lyndsy Fonseca .