It's Always Sunny in Philadelphia (2005)

S17E6 Overage Drinking: A National Concern

Title: Underage Drinking: A National Crisis Plot: Tammy and Trey, now in their 40s, arrive to take their teenage son out of Paddy's, prompting Dennis and Dee to seek a reunion with their old prom dates. Meanwhile, Frank goes missing unexpectedly, leading Mac and Charlie on a quest to uncover his location.