Season 2: Episode 19 - Bachelor Party

Bachelor Party: When Barney ruins Marshall's bachelor party by hiring a stripper he absolutely didn’t want, Marshall questions whether he should even invite Barney to the wedding since he has been against it from the beginning. However, after Lily reveals a secret about Barney, Marshall makes Barney his best man. Also, Robin follows Barney’s advice and buys Lily an extremely racy gift for her bridal shower but is mortified when she arrives at a wholesome family shower.