Bartholomew "Bart" Simpson is voiced by Nancy Cartwright (that's right, a woman!) and is Homer and Marge's only son on The Simpsons. Bart is an underachiever and was definitely much more of a bad boy in th ebeginning seasons of the show.
Now, Bart, although he has not aged, has certainly matured as a character. Do the Bartman people.
Bart: Hey, Mom. Did you save Dad's love letters?
Marge: Of course I saved them. Well actually, there's only one. It's more of a love postcard from some brewery he visited.
Homer: Maybe it's the beer talking, Marge. But you've got a butt that won't quit. They've got these big chewy pretzels here (undecipherable slurring) five dollars?! Get outta here!
Bart: Wow, the side of Dad I've never seen.
(Picking out a Tuxedo for Bart. He doesn't look pleased with his puffy shirt tuxedo.)
Bart: (frowning) Isn't this shirt kinda gay?
Clerk: Last time I checked, pirates weren't gay.
Homer: Eww, how'd you check?