Best Prom Ever

At the beginning of the episode, Marshall discovers that the location where he and Lily would like to have their wedding, the Van Smoot House, has an unexpected opening. They hurriedly book the available date, leaving only two months until the wedding. Lily becomes very stressed due to the shortened timeframe and obsesses over the details, becoming somewhat of a bridezilla.

Marshall finds a possible band for the wedding, The 88, but Lily will not approve the booking until she hears them play "their" song ("Good Feeling" by Violent Femmes). The only way Lily can hear them is if she sneaks into a high school prom where they are playing. Lily thus decides to sneak in with Robin and Barney. Robin is excited, because she never had the chance to attend her prom in high school, having been too busy with field hockey tournaments. This is later assumed to be a lie as Robin had yet to reveal her past as Robin Sparkles. When they arrive, they find tight security, so Lily and Robin offer to be the dates of two nerdy high school seniors, while Barney decides to find another way in.

Meanwhile, Ted and Marshall are stuffing wedding invitations on their "Guys' Night Out" until Robin calls Marshall and asks him to bring the sheet music of "Good Feeling" to Lily. Lily remembers her senior prom and all she had thought she'd experience but never did. She begins to have doubts about getting married, since she never achieved many of her goals in life. She tells this to Robin, who convinces her that she is marrying her best friend in the world, and that she could possibly be an artist and live an artist's lifestyle later in life. She then kisses her on the lips, giving Lily the "lesbian experience" she never had.

Ted and Marshall sneak in the back, and find Barney dressed as a turtle mascot. Marshall asks the senior who's Lily's date for the night where she is, who then pulls out a pair of Nunchaku and hits Marshall with them. Ted then tackles the senior to show Marshall that he will always have his back in a fight. The two seniors, Marshall, Ted, and Barney are taken outside for trespassing, but Marshall and Ted sneak back in when Barney grabs the head of the turtle mascot suit and runs off. Marshall and Lily dance together, and agree to have The 88 play at the wedding, while Ted dances with Robin, who now wants to try restoring their relationship.

Ryan Budke of TV Squad wrote how the flashbacks in the episode lent some real credibility to Lily's doubts about getting married, going on to say how he loved the line about how her doubts weren't in him, they were in her. The truth of this line he says shows "why this show isn't just a Friends clone".[1]

• "Best Prom Ever" at IMDb
• "Best Prom Ever" at TV.com