Changing your club allegiance is bad enough - but switching which country you support, now that is criminal.
That's exactly what famous Paraguayan glamour model Larissa Riquelme has done, though. Back in 2010, she was supporting her nation during the World Cup in South Africa, watching on from afar as they progressed to the quarter-finals.
Larissa, who shot to fame during the tournament after being papped with her mobile phone between her breasts, even gave them extra motivation by promising to do a naked magazine shoot if they made it to the final four.
However, Paraguary were knocked out by eventual winners Spain. And 12 years, on they didn't even qualify for the 2022 finals in Qatar.
So Larissa decided to pick another South American nation to get behind. She shared a snap of herself wearing a Brazil-themed green and yellow one-piece bikini last week to her 1.9million Instagram followers.
Of course, she completed the look by placing the same mobile phone which helped her go viral back in the middle of her chest.
Larissa had also vowed to run through the streets wearing just the blue, white and red colours of Paraguay in body paint if they could have shocked the world and won the 2010 tournament.
While that didn't materialise, her naked photo shoot eventually did - because later that year she posed for the September edition of Playboy Brazil.
Then aged just 25, the 37-year-old's World Cup appearances changed her life completely. She is now one of the highest-paid models in Paraguay and appeared on the Argentinian version of Dancing with the Stars.
She became the face of the deodorant brand Axe in her home country, which saw her sport the company's name in permanent marker on her boobs during the World Cup quarter-final defeat.
Despite her fame and the temporary switch to Brazil, Larissa has continued to support Paraguay in the years since and was spotted cheering them on at the 2019 Copa America.
As well as modelling, she's worked as a television presenter and dabbled in acting. Her Qatar hopefuls Brazil will be looking to book their place in the quarter-finals when they take on South Korea in the last 16 later today (December 5).