Celebs John C. Reilly jumped on stage to sing at a Boston dive bar "Step Brothers" star John C. Reilly was visiting a Boston dive bar with a friend. Actor John C. Reilly performing a song at Tavern at the End of the World, a dive bar in Boston near the Somerville border. Tavern at the End of the World; Getty Images“Step Brothers” actor John C. Reilly has been making the rounds in the Boston area recently — including for an impromptu late-night performance at a local dive bar. Advertisement:Following his late-night revelry at Tavern at the End of the World, Reilly also stayed local the next morning, visiting Kelly’s Diner in Somerville for breakfast. Legendary Actor John C Reilly knows where to go for the best breakfast,” Kelly’s owner Jay Holmes wrote on Facebook.