It's Always Sunny In Philadelphia Season 12: 10 Funniest Moments

The plot of The Gang Tends Bar is a prime example of a plan being doomed to fail from the start; as Dennis' bid to efficiently run the bar for once is taken off the rails by the rest of the gangs' antics. This all builds up to the episode's climax: a rapid-fire cavalcade of disarray which is diffused by rather unusual means.

Dee is upset that she got a Valentine's Day card for Charlie, and received nothing in return. To make matters worse, Charlie is ignoring Dee so he can focus on winning Frank's friendship back from his tapeworm. (Just go with it.) Ultimately, this comes to a head and results in a rather comical shouting match.

Dee then ups the ante by bringing a bag of anthrax into the fold and threatening to kill everyone unless Charlie sings her a Valentine's song for her. It's so unbelievably excessive, yet so in character, that it works perfectly.

What follows is the funniest use of Charlie's poor grasp of the English language of the season, as she essentially has to coach him through the song as he fails to create even the simplest rhymes. Then, when the song is over, she ruthlessly mocks him for actually doing it.

All's well that ends well.