It's Always Sunny in Philadelphia - Season 5 Episode 12 -
The Gang Reignites the Rivalry
After being banned for 10 years from a local drinking competition appropriately named "Flipadelphia," the gang tries to reignite their old rivalry with another local bar. Finding that they are in need of some serious practice, the guys head to Dennis' old fraternity house at the University of Pennsylvania to get their game up to speed while Dee hones her skills on her own. Frank wears skinny pants.