Bart Simpson got in hot water for it on a trip Down Under, but now real-life Australians could face jail time for mooning.
An amendment passed by the Victorian Government has made it a specific offence under the Summary Offences Act, which now reads: "Behaviour that is indecent, offensive or insulting includes behaviour that involves a person exposing (to any extent) the person's anal or genital region."
It means those exposing themselves in public can be jailed for up to two months, and repeat offenders could be locked up for up to six months.
Previously, mooning could be punishable under other laws, but there wasn't a specific offence.
The amendment was one of more than 50 introduced in major changes of sexual violence laws, and means people who moon won't be charged with sexual exposure.
"Sexual exposure is of course a much more serious offence," Attorney General Martin Pakula told 3AW.
"We don't want a situation where someone who might streak at the cricket is funnelled into the same category as someone who might jump out in front of a 13-year-old girl and flash.
"They're very different types of offences and the legislation for the first time makes that clear."
Mr Pakula says if the law didn't allow for punishment of mooning, people could get a little cheeky.
"If you contemplate a situation where it's not [an offence] you could have people simply doing it every day with no possibility of any kind of sanction."
The fictional Simpson family caused diplomatic outrage in an episode where they're brought to Australia to publicly apologise after Bart racks up a large international phone bill.
Having done so, the Parliament reveals it wants to punish him by kicking him in the buttocks with a giant boot - much to the shock of the family.
After some negotiation, the punishment is downgraded to a kick in the buttocks by the Prime Minister with a normal shoe, and through the gates of the US Embassy.
Bart agrees, but when the jumps out of the way at the last second before mooning the Prime Minister and those gathered at the gates with the words "don't tread on me" written on his buttocks - at which point the family flees in a helicopter.