Lily, Barney and Robin attend a high school prom to scout out a potential band for Lily and Marshall's wedding reception. In order to get in Lily and Robin pretend to be the dates of two kids who were going alone. Ted and Marshall are back at the apartment where they are preparing the invitations to be sent out.
click here to see where to watch or .
Ready to Watch How I Met Your Mother, Season 1, Episode 20?