Watch It's Always Sunny in Philadelphia Season 5 Episode 12 "The Gang Reignites The Rivalry" online here:

http://www.tvshowslist.com/its-always-sunny-in-philadelphia-season-5-episode-12-the-gang-reignites-the-rivalry/

The gang reenters Philadelphia’s flip-cup tournament (the Flipadelphia) after being banned for 10 years. Trouble is, their old flip-cup rivals have grown up and moved on.