The Italian Bob (S17, E08-364)

As long as he doesn't say "vendetta", that kid can be as menacing as he wants.

Plot Summary
Mr. Burns buys a new Italian sportscar, but has Homer retrieve it manually from Italy so that he doesn't have to pay taxes for it.  Homer gets to bring the family along to get the car, and they have to drive it to Rome to have it shipped.  Despite that, the family does some sightseeing first which winds up with the car getting smashed by a giant block of cheese.  They go to the nearest town to get help, but only one person in town speaks English: the mayor.  They go visit the mayor to learn to their shock that the mayor is actually Sideshow Bob!

Bob reveals that, after his last attempt at killing Bart 'failed', he decided he needed a fresh start, and half-randomly moved to a Tuscan village.  There, his large feet prove vital in creating a large wine harvest, and becomes so celebrated he's voted in as the mayor of the town.  He even found a woman to be his wife and together they had a son (the two are both aware of Bart as Bob screams out his name at night).  Bob tells them that nobody in the village is aware of his dubious past, and he agrees to fix their car in exchange for their silence.  Things go pretty well, but in a celebration feast Lisa gets drunk from wine and lets out Bob's big secret to the entire town.  Bob is disgraced and swears vengeance on the fleeing Simpson family.

During the escape, the Simpson family wrecks Burns' car again but they're able to flee Bob's notice.  Bob is about to give up again, but is encouraged by his wife and child to follow through on his vengeance, as they too have been shamed by the Simpsons.  The Simpsons make it to Rome, where they realize that Krusty the Klown is in town to perform a play.  They ask for his help, and he tries to have them hide within a background character cast in the play he's poorly performing, but Bob and family find the Simpsons and try to kill them on stage.  Krusty is able to secure the family's escape, though, and they get to go back to America.  Bob and his family is at first disappointed, but they soon get motivated again as they bond over getting vengeance.

Quick Review
This... this was not a good episode.  The premise was pretty bad from the start, Bob having a kid already was 'we know continuity is messed up so here you go anyway, suckers' level stupid, and that kid going 'vendetta' over and over again got too annoying for its own good.  Krusty the Klown tries his best to salvage the episode at the end, but its far too little, far too late.  By far, this is the worst Sideshow Bob episode of the show.

Final Score: 5.1